H323 problems

Under high load H323 crashes and kills Asterisk, debug shows:

(gdb) bt
#0  0x007a2b18 in strcmp () from /lib/libc.so.6
#1  0x014478a1 in find_call_locked (call_reference=13, token=0xa1cc570 "ip$81.192.72.46:7768/13") at chan_h323.c:1148
#2  0x01449f07 in cleanup_connection (call_reference=13, call_token=0xa1cc570 "ip$81.192.72.46:7768/13") at chan_h323.c:2290
#3  0x0145a724 in MyH323EndPoint::OnConnectionCleared () from /usr/lib/asterisk/modules/chan_h323.so
#4  0x00e604f1 in H323Connection::OnCleared () from /usr/local/lib/libh323_linux_x86_r.so.1.18.0
#5  0x00e721d1 in H323EndPoint::CleanUpConnections () from /usr/local/lib/libh323_linux_x86_r.so.1.18.0
#6  0x00e722fe in H323ConnectionsCleaner::Main () from /usr/local/lib/libh323_linux_x86_r.so.1.18.0
#7  0x005fd6e5 in PThread::PX_ThreadStart () from /usr/local/lib/libpt_linux_x86_r.so.1.10.0
#8  0x0088446b in start_thread () from /lib/libpthread.so.0
#9  0x00804dbe in clone () from /lib/libc.so.6

Server 2x XEON quad core and 4g DDR crashes on 110-120 simm. H323 calls.