weird segfault on chunk_alloc() /*called by malloc()*/

[plex15]

Hi :)
I use Debian 2.2 GNU/Linux..
and a made a little program, but it crashes on malloc sometimes..
I don't know if it is a bug on the glibc, or in my program..
but i think it's not normal crashes in malloc()..
you can get the source code of my program in 
http://htsr0x.virtualave.net/code.tar.gz
the program acess a http server..
it's not a backdoor or any joke of any kind.
sorry for my poor english :)
,
hts.