memory allocation bug in g++-4.1.2 and glibc

[alikin]

Hi,
My C++ code behaves strangely and breaks at some unexpected point with
an error message from libc about corrupted memory. Valgrind shows that
there is no memory leak in my program and it does work all fine for
some inputs and breaks for some others.
my system is debian testing and "g++ -v" gives:
gcc version 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)
Here is the output of gdb:
(gdb) bt
#0  0x402b0947 in raise () from /lib/tls/libc.so.6
#1  0x402b20c9 in abort () from /lib/tls/libc.so.6
#2  0x402e5fda in __fsetlocking () from /lib/tls/libc.so.6
#3  0x402ee3f3 in free () from /lib/tls/libc.so.6
#4  0x402efc4f in malloc () from /lib/tls/libc.so.6
#5  0x40222908 in operator new () from /usr/lib/libstdc++.so.6
#6  0x40222a3d in operator new[] () from /usr/lib/libstdc++.so.6

I did a bit of search and apparently this problem is common in g++4.*
but g++-3.4 works fine. But unfortunately I can't revert to that
version unless I change my code abit to handle private friend virtual
functions correctly(which I don't know how..)
Any help on how to get g++-4.1.2 work properly is greatly appreciated.
cheers,
Alikin