Not able to connect using Sybase ASE using freeTDS

Hi Guys,
I am not able to connect to Sybase Adaptive server 15.5 on linux using
freetds earlier, using freetds v0.92.dev.20111217.
Bypassing the configuration settings I am trying to connect to Sybase ASE
using command
TDSVER=5.0 tsql -H 10.1.33.19 -U sa -p 5000 -P, I am getting the following
error.
locale is "en_US.UTF-8"
locale charset is "UTF-8"
using default charset "UTF-8"
Error 20009 (severity 9):
        Unable to connect: Adaptive Server is unavailable or does not exist
        OS error 115, "Operation now in progress"
There was a problem connecting to the server
*freetds error log show this*
log.c:194:Starting log file for FreeTDS 0.92.dev.20111217
on 2012-02-28 10:34:03 with debug flags 0x4fff.
iconv.c:328:tds_iconv_open(0x82f2aa8, UTF-8)
iconv.c:185:local name for ISO-8859-1 is ISO-8859-1
iconv.c:185:local name for UTF-8 is UTF-8
iconv.c:185:local name for UCS-2LE is UCS-2LE
iconv.c:185:local name for UCS-2BE is UCS-2BE
iconv.c:347:setting up conversions for client charset "UTF-8"
iconv.c:349:preparing iconv for "UTF-8" <-> "UCS-2LE" conversion
iconv.c:389:preparing iconv for "ISO-8859-1" <-> "ISO-8859-1" conversion
iconv.c:392:tds_iconv_open: done
net.c:203:Connecting to 10.1.33.19 port 5000 (TDS version 4.2)
net.c:269:tds_open_socket: connect(2) returned "Operation now in progress"
net.c:315:tds_open_socket() failed
util.c:315:tdserror(0x82f2900, 0x82f2aa8, 20009, 115)
util.c:345:tdserror: client library returned TDS_INT_CANCEL(2)
util.c:368:tdserror: returning TDS_INT_CANCEL(2)
mem.c:594:tds_free_all_results()

I  am able to connect from the database server machine with command *isql*.
Could any one help me on this?
Earlier I was able to connect using the tsql to another Sybase instance.
While accessing the new instance of Sybase I am getting this error.
Could anyone point me out that is there any configuration issues at Sybase
server causing this problem?

Thanks,
Rajeev