Virtual Memory exceeded

Hi,

We've got some trouble with bro...
After about 2 hours running bro (mt script), bro crash with a :
"Virtual Memory exceeded in 'new'" Error.

Can someone suggest me what I can do about this (I've already increased
RAM and swap from 32Mb to 64Mb) ?
Is there a way to check what part of bro is taking whole this memory (stream
buffers or active sessions table, ...)

Config PC:
Pentium 200 Mhz
64 Mb RAM

Config OS:
Redhat 5.2
64 Mb Swap space.
original 486 kernel version (I didn't recompile kernel to be sure to have
the most standard config).
no errors reported in syslog

Config BRO:
bro 0.5a
script mt.bro

regards,

Patrick Verstraete
Alexandre Dumortier
Universite catholique de Louvain, Belgium

Here follows status taken every ten minutes.
FLAGS UID PID PPID PRI NI SIZE RSS WCHAN STA TTY TIME
COMMAND
Thu Apr 29 17:17:47 CEST 1999
100100 0 1164 890 9 5 28308 27760 R N p0 0:26 bro
-i et
Thu Apr 29 17:20:00 CEST 1999
100100 0 1164 890 10 5 34328 33780 skb_recv_da S N p0 0:32 bro
-i et
Thu Apr 29 17:30:00 CEST 1999
100100 0 1164 890 9 5 56952 56392 skb_recv_da S N p0 0:53 bro
-i et
Thu Apr 29 17:40:01 CEST 1999
100100 0 1164 890 12 5 75260 58088 R N p0 1:10 bro
-i et
Thu Apr 29 17:50:01 CEST 1999
100100 0 1164 890 9 5 89332 58000 skb_recv_da S N p0 1:27 bro
-i et
Thu Apr 29 18:00:02 CEST 1999
100100 0 1164 890 17 5 102876 59004 skb_recv_da S N p0 1:49 bro
-i et