Panic upon receiving SMS

I've a Wavecom modem and when I receive an SMS the bearerbox panics, can 
anyone help ?


my config:
------------------------
group = smsc
smsc-id = ricevitore
smsc = at
modemtype = auto
device = /dev/ttyS0
speed = 9600

group = modems
id = wavecom
name = Wavecom
detect-string = "WAVECOM"

group = sms-service
get-url = 
"http://MY-DOMAIN/showsubmitted.php3?text=%a&timestamp=%T&sender=%p&receiver=%P"
------------------------

2005-04-12 13:34:20 [5619] [5] DEBUG: AT2[ricevitore]: <-- +CMT: ,54
2005-04-12 13:34:20 [5619] [5] DEBUG: AT2[ricevitore]: <-- 
0791932350593900040C9193336553595139105040213192958027D3F2F8ED26BF41F4F29C0E9A97DDFA3028EDA697E7F4B03EFD769741E2B43B2C4F8701
2005-04-12 13:34:20 [5619] [5] DEBUG: AT2[ricevitore]: Numeric sender 
(international) <+393356359515>
2005-04-12 13:34:20 [5619] [5] DEBUG: AT2[ricevitore]: User data length 
read as (39)
2005-04-12 13:34:20 [5619] [5] DEBUG: AT2[ricevitore]: Udh decoding done 
len=39 udhi=0 udhlen=0 udh=''
2005-04-12 13:34:20 [5619] [5] PANIC: gwlib/gw-rwlock.c:137: 
gw_rwlock_rdlock: Assertion `lock != NULL' failed.
2005-04-12 13:34:20 [5619] [5] PANIC: bearerbox(gw_panic+0x175) [0x80c9d56]
2005-04-12 13:34:20 [5619] [5] PANIC: bearerbox(gw_rwlock_rdlock+0x36) 
[0x80bf326]
2005-04-12 13:34:20 [5619] [5] PANIC: 
bearerbox(route_incoming_to_boxc+0x70) [0x80560f7]
2005-04-12 13:34:20 [5619] [5] PANIC: 
bearerbox(bb_smscconn_receive+0x333) [0x8058002]
2005-04-12 13:34:20 [5619] [5] PANIC: bearerbox [0x8064d52]
2005-04-12 13:34:20 [5619] [5] PANIC: bearerbox [0x8065f84]
2005-04-12 13:34:20 [5619] [5] PANIC: bearerbox [0x80bfa1c]
2005-04-12 13:34:20 [5619] [5] PANIC: /lib/tls/libpthread.so.0 [0x4007e2b6]
2005-04-12 13:34:20 [5619] [5] PANIC: /lib/tls/libc.so.6(__clone+0x57) 
[0x420de407]