pb with jain-sip-presence-proxy : 500 Server Internal Error

I try to work with the jain-sip-presence-proxy, i use linphone (VoIP 
application) just to try the proxy, but i have always the "500 Server Internal 
Error"
i don't know why !
It can be nice if you can help me ...

i have the following configuration (very basic) :

(192.168.18.63)      (192.168.18.64)         (192.168.18.65)
PC A                  PC proxy                PC B
linphone              jain-sip                linphone
   |----------------------|-----------------------|

in the server DNS installed onto the PC proxy, the PC proxy is named : "flaviol"



the 2 linphone are correctly registered in the proxy, with the sip @ :
   sip:coltranej@flaviol (for the PC A)
   sip:sirejl@flaviol (for the PC B)

If i try to call "sip:sirejl@flaviol" from the PC A :

(192.168.18.63)            (192.168.18.64)         (192.168.18.65)
PC A                       PC proxy                PC B
linphone                   jain-sip                linphone
   |---------------------------|-----------------------|
   ----------( invite )-------->
   <---(500 srv int. error)----
   ------------( ack )--------->




Here is the console logging :


[java] Request INVITE received:
[java] INVITE sip:sirejl@flaviol SIP/2.0
[java] Via: SIP/2.0/UDP 192.168.18.63:5060;rport;branch=z9hG4bK1319803317
[java] From: <sip:coltranej@flaviol>;tag=719951855
[java] To: <sip:sirejl@flaviol>
[java] Call-ID: [email protected]
[java] CSeq: 20 INVITE
[java] Contact: <sip:[email protected]:5060>
[java] Max-Forwards: 5
[java] User-Agent: Linphone-1.6.0/eXosip
[java] Subject: Phone call
[java] Expires: 120
[java] Allow: INVITE,ACK,CANCEL,BYE,OPTIONS,REFER,SUBSCRIBE,NOTIFY,MESSAGE
[java] Content-Type: application/sdp
[java] Content-Length: 428
[java] v=0
[java] o=coltranej 123456 654321 IN IP4 192.168.18.63
[java] s=A conversation
[java] c=IN IP4 192.168.18.63
[java] t=0 0
[java] m=audio 7078 RTP/AVP 111 110 0 3 8 101
[java] a=rtpmap:111 speex/16000/1
[java] a=rtpmap:110 speex/8000/1
[java] a=rtpmap:0 PCMU/8000/1
[java] a=rtpmap:3 GSM/8000/1
[java] a=rtpmap:8 PCMA/8000/1
[java] a=rtpmap:101 telephone-event/8000
[java] a=fmtp:101 0-11
[java] m=video 9078 RTP/AVP 98 99
[java] a=rtpmap:98 H263-1998/90000
[java] a=fmtp:98 CIF=1;QCIF=1
[java] a=rtpmap:99 MP4V-ES/90000
[java] 43551 [EventScannerThread] DEBUG gov.nist.sip.proxy.ProxyUtilities  - 
DEBUG TRANSACTION INFO: the transaction is null
[java] 43551 [EventScannerThread] DEBUG proxy-jiji  - 
gov.nist.javax.sip.stack.SIPTransactionStack.isDialogCreated
(SIPTransactionStack.java:363) [isDialogCreated : INVITE returning true]
[java] 43551 [EventScannerThread] DEBUG proxy-jiji  - 
gov.nist.javax.sip.stack.SIPTransactionStack.findTransaction
(SIPTransactionStack.java:613) [serverTx: looking for key z9hg4bk1319803317 
existing=
{z9hg4bk1362009468=gov.nist.javax.sip.stack.SIPServerTransaction@8ad25aba, 
z9hg4bk1428521171=gov.nist.javax.sip.stack.SIPServerTransaction@c59835bf}]
[java] 43555 [EventScannerThread] DEBUG proxy-jiji  - 
gov.nist.javax.sip.stack.SIPTransactionStack.addTransaction
(SIPTransactionStack.java:1093) [added transaction 
gov.nist.javax.sip.stack.SIPServerTransaction@35c1f87]
[java] 43579 [EventScannerThread] DEBUG proxy-jiji  - 
gov.nist.javax.sip.stack.SIPServerTransaction$SendTrying.<init>
(SIPServerTransaction.java:239) [scheduled timer for 
gov.nist.javax.sip.stack.SIPServerTransaction@35c1f87]
[java] 43582 [EventScannerThread] DEBUG proxy-jiji  - 
gov.nist.javax.sip.stack.SIPTransactionStack.removePendingTransaction
(SIPTransactionStack.java:740) [removePendingTx: z9hg4bk1319803317]
[java] 43582 [EventScannerThread] DEBUG proxy-jiji  - 
gov.nist.javax.sip.stack.SIPTransactionStack.addTransactionHash
(SIPTransactionStack.java:1115) [ putTransactionHash :  key = z9hg4bk1319803317]
[java] 43582 [EventScannerThread] DEBUG proxy-jiji  - 
gov.nist.javax.sip.stack.SIPServerTransaction$TransactionTimer.<init>
(SIPServerTransaction.java:272) [TransactionTimer() : z9hg4bk1319803317]
[java] 43583 [EventScannerThread] DEBUG gov.nist.sip.proxy.Proxy  - Proxy, 
processRequest(), we are responsible for the domain... Let's find the contact...
[java] 43583 [EventScannerThread] DEBUG gov.nist.sip.proxy.Proxy  - Proxy, 
processRequest(), we canonicalized the request-URI
[java] 43583 [EventScannerThread] DEBUG 
gov.nist.sip.proxy.registrar.RegistrationsTable  - RegistrationsTable, 
hasRegistration(), Checking registration for "sip:sirejl@flaviol" : registered
[java] 43583 [EventScannerThread] DEBUG gov.nist.sip.proxy.Proxy  - Proxy, 
processRequest(), the target set is the set of the contacts URI from the  
location service
[java] 43600 [EventScannerThread] DEBUG gov.nist.sip.proxy.RequestForwarding  - 
RequestForwarding, forwardRequest() (STEP 1), the request is cloned
[java] 43600 [EventScannerThread] DEBUG gov.nist.sip.proxy.RequestForwarding  - 
RequestForwarding, forwardRequest() (STEP 2), The Request-URI in the copy's 
start line is replaced with the URI for this target
[java] 43601 [EventScannerThread] DEBUG gov.nist.sip.proxy.RequestForwarding  - 
RequestForwarding, forwardRequest(),  (STEP 3) MaxForwardHeader  decremented by 
one.
[java] 43604 [EventScannerThread] ERROR gov.nist.sip.proxy.RequestForwarding  - 
RequestForwarding, forwardRequest(),  internal error, exception raised:
[java] java.lang.NullPointerException: null host
[java] at gov.nist.javax.sip.address.AddressFactoryImpl.createSipURI
(AddressFactoryImpl.java:79)
[java] at gov.nist.sip.proxy.RequestForwarding.forwardRequest(Unknown Source)
[java] at gov.nist.sip.proxy.Proxy.processRequest(Unknown Source)
[java] at gov.nist.javax.sip.EventScanner.deliverEvent(EventScanner.java:162)
[java] at gov.nist.javax.sip.EventScanner.run(EventScanner.java:404)
[java] at java.lang.Thread.run(Thread.java:595)
[java] 43697 [EventScannerThread] DEBUG proxy-jiji  - 
gov.nist.javax.sip.stack.SIPTransaction.setState(SIPTransaction.java:504) 
[Transaction:setState Completed Transaction 
gov.nist.javax.sip.stack.SIPServerTransaction@35c1f87 branchID = 
z9hG4bK1319803317 isClient = false]
[java] 43697 [EventScannerThread] DEBUG proxy-jiji  - 
gov.nist.core.LogWriter.logStackTrace(LogWriter.java:101) 
[[SIPTransaction.java:507][SIPServerTransaction.java:1311]
[SIPServerTransaction.java:842][SIPServerTransaction.java:1264][null:-1][null:-
1][EventScanner.java:162][EventScanner.java:404][Thread.java:595]]
[java] 43698 [EventScannerThread] DEBUG proxy-jiji  - 
gov.nist.javax.sip.stack.SIPTransaction.enableTimeoutTimer
(SIPTransaction.java:558) [enableTimeoutTimer 
gov.nist.javax.sip.stack.SIPServerTransaction@35c1f87 tickCount 64 
currentTickCount = -1]
[java] 43698 [EventScannerThread] DEBUG proxy-jiji  - 
gov.nist.javax.sip.stack.SIPServerTransaction.sendMessage
(SIPServerTransaction.java:940) [sendMessage : tx = 
gov.nist.javax.sip.stack.SIPServerTransaction@35c1f87 getState = Completed 
Transaction]
[java] 43698 [EventScannerThread] DEBUG proxy-jiji  - 
gov.nist.javax.sip.stack.UDPMessageChannel.<init>(UDPMessageChannel.java:169) 
[Creating message channel 192.168.18.63/5060]
[java] 43699 [EventScannerThread] DEBUG proxy-jiji  - 
gov.nist.core.LogWriter.logStackTrace(LogWriter.java:101) 
[[UDPMessageChannel.java:509][SIPServerTransaction.java:396]
[SIPServerTransaction.java:945][SIPServerTransaction.java:1264][null:-1][null:-
1][EventScanner.java:162][EventScanner.java:404][Thread.java:595]]
[java] 43699 [EventScannerThread] DEBUG proxy-jiji  - 
gov.nist.javax.sip.stack.UDPMessageChannel.sendMessage
(UDPMessageChannel.java:609) 
[gov.nist.javax.sip.stack.UDPMessageChannel:sendMessage 192.168.18.63/5060
[java] SIP/2.0 500 Server Internal Error