when someone login in at M$ messenger the msgsnarf crashes

Messenger version 2009, latest version with Messenger plus latest v. too

(it's a network where backtrack shares the inet to several computers,
backtrack is installed at local disk)

root@bt:~# msgsnarf
msgsnarf: listening on eth0
*** glibc detected *** msgsnarf: free(): invalid pointer: 0xb7fbd170 ***
======= Backtrace: =========
/lib/tls/i686/cmov/libc.so.6[0xb7ed1454]
/lib/tls/i686/cmov/libc.so.6(cfree+0x96)[0xb7ed34b6]
msgsnarf[0x8049561]
msgsnarf[0x8048fd7]
/usr/lib/libnids.so.1.21[0xb8005442]
/usr/lib/libnids.so.1.21[0xb8005c4f]
/usr/lib/libnids.so.1.21[0xb8005daf]
/usr/lib/libnids.so.1.21(process_tcp+0x85a)[0xb8006a3a]
/usr/lib/libnids.so.1.21[0xb800485f]
/usr/lib/libnids.so.1.21[0xb80049d4]
/usr/lib/libnids.so.1.21(nids_pcap_handler+0xa4)[0xb8004c04]
/usr/lib/libpcap.so.0.8[0xb7fd9ea9]
/usr/lib/libpcap.so.0.8(pcap_loop+0x6b)[0xb7fdbfbb]
/usr/lib/libnids.so.1.21(nids_run+0x56)[0xb8004196]
msgsnarf[0x8048e26]
/lib/tls/i686/cmov/libc.so.6(__libc_start_main+0xe5)[0xb7e78685]
msgsnarf[0x8048c61]
======= Memory map: ========
08048000-0804c000 r-xp 00000000 03:02 77841 /usr/sbin/msgsnarf
0804c000-0804d000 rw-p 00003000 03:02 77841 /usr/sbin/msgsnarf
0804d000-0806e000 rw-p 0804d000 00:00 0 [heap]
b7c00000-b7c21000 rw-p b7c00000 00:00 0
b7c21000-b7d00000 ---p b7c21000 00:00 0
b7d20000-b7d2d000 r-xp 00000000 03:02 175024 /lib/libgcc_s.so.1
b7d2d000-b7d2e000 r--p 0000c000 03:02 175024 /lib/libgcc_s.so.1
b7d2e000-b7d2f000 rw-p 0000d000 03:02 175024 /lib/libgcc_s.so.1
b7d2f000-b7d58000 rw-p b7d2f000 00:00 0
b7d58000-b7d80000 r-xp 00000000 03:02 175077 /lib/libpcre.so.3.12.1
b7d80000-b7d81000 r--p 00027000 03:02 175077 /lib/libpcre.so.3.12.1
b7d81000-b7d82000 rw-p 00028000 03:02 175077 /lib/libpcre.so.3.12.1
b7d82000-b7d97000 r-xp 00000000 03:02 57464 /lib/tls/i686/cmov/libpthread-2.8.90.so
b7d97000-b7d98000 r--p 00014000 03:02 57464 /lib/tls/i686/cmov/libpthread-2.8.90.so
b7d98000-b7d99000 rw-p 00015000 03:02 57464 /lib/tls/i686/cmov/libpthread-2.8.90.so
b7d99000-b7d9b000 rw-p b7d99000 00:00 0
b7d9b000-b7da2000 r-xp 00000000 03:02 57466 /lib/tls/i686/cmov/librt-2.8.90.so
b7da2000-b7da3000 r--p 00007000 03:02 57466 /lib/tls/i686/cmov/librt-2.8.90.so
b7da3000-b7da4000 rw-p 00008000 03:02 57466 /lib/tls/i686/cmov/librt-2.8.90.so
b7da4000-b7da5000 rw-p b7da4000 00:00 0
b7da5000-b7e5a000 r-xp 00000000 03:02 75378 /usr/lib/libglib-2.0.so.0.1800.2
b7e5a000-b7e5b000 r--p 000b4000 03:02 75378 /usr/lib/libglib-2.0.so.0.1800.2
b7e5b000-b7e5c000 rw-p 000b5000 03:02 75378 /usr/lib/libglib-2.0.so.0.1800.2
b7e5c000-b7e60000 r-xp 00000000 03:02 75381 /usr/lib/libgthread-2.0.so.0.1800.2
b7e60000-b7e61000 r--p 00003000 03:02 75381 /usr/lib/libgthread-2.0.so.0.1800.2
b7e61000-b7e62000 rw-p 00004000 03:02 75381 /usr/lib/libgthread-2.0.so.0.1800.2
b7e62000-b7fba000 r-xp 00000000 03:02 57450 /lib/tls/i686/cmov/libc-2.8.90.so
b7fba000-b7fbc000 r--p 00158000 03:02 57450 /lib/tls/i686/cmov/libc-2.8.90.so
b7fbc000-b7fbd000 rw-p 0015a000 03:02 57450 /lib/tls/i686/cmov/libc-2.8.90.so
b7fbd000-b7fc0000 rw-p b7fbd000 00:00 0
b7fc0000-b7fd3000 r-xp 00000000 03:02 59630 /usr/lib/libnet.so.1.3.0
b7fd3000-b7fd4000 rw-p 00013000 03:02 59630 /usr/lib/libnet.so.1.3.0
b7fd4000-b7fd5000 rw-p b7fd4000 00:00 0
b7fd5000-b7ffe000 r-xp 00000000 03:02 59726 /usr/lib/libpcap.so.0.9.8
b7ffe000-b7fff000 r--p 00028000 03:02 59726 /usr/lib/libpcap.so.0.9.8
b7fff000-b8000000 rw-p 00029000 03:02 59726 /usr/lib/libpcap.so.0.9.8
b8000000-b8008000 r-xp 00000000 03:02 59646 /usr/lib/libnids.so.1.21
b8008000-b8009000 r--p 00007000 03:02 59646 /usr/lib/libnids.so.1.21
b8009000-b800a000 rw-p 00008000 03:02 59646 /usr/lib/libnids.so.1.21
b800a000-b801f000 r-xp 00000000 03:02 57456 /lib/tls/i686/cmov/libnsl-2.8.90.so
b801f000-b8020000 r--p 00014000 03:02 57456 /lib/tls/i686/cmov/libnsl-2.8.90.so
b8020000-b8021000 rw-p 00015000 03:02 57456 /lib/tls/i686/cmov/libnsl-2.8.90.so
b8021000-b8023000 rw-p b8021000 00:00 0
b8023000-b8033000 r-xp 00000000 03:02 57465 /lib/tls/i686/cmov/libresolv-2.8.90.so
b8033000-b8034000 r--p 0000f000 03:02 57465 /lib/tls/i686/cmov/libresolv-2.8.90.so
b8034000-b8035000 rw-p 00010000 03:02 57465 /lib/tls/i686/cmov/libresolv-2.8.90.so
b8035000-b8037000 rw-p b8035000 00:00 0
b8046000-b8048000 rw-p b8046000 00:00 0
b8048000-b8062000 r-xp 00000000 03:02 59790 /lib/ld-2.8.90.so
b8062000-b8063000 rw-p b8062000 00:00 0
b8063000-b8064000 r--p 0001a000 03:02 59790 /lib/ld-2.8.90.so
b8064000-b8065000 rw-p 0001b000 03:02 59790 /lib/ld-2.8.90.so
bfd4f000-bfd64000 rw-p bffeb000 00:00 0 [stack]
ffffe000-fffff000 r-xp 00000000 00:00 0 [vdso]
Aborted