double free or corruption - it works on older machine

[alan . larkin]

I have software that works on an old machine:
Linux 2.4.20-8smp #1 SMP i686 i686 i386 GNU/Linux
gcc (GCC) 3.2.2 20030222 (Red Hat Linux 3.2.2-5)

But not on a new one:
Linux 2.6.15-26-amd64-generic #1 SMP PREEMPT x86_64 GNU/Linux
gcc (GCC) 4.0.3 (Ubuntu 4.0.3-1ubuntu5)
(also has gcc 3.3 and 3.4)

I get a "*** glibc detected *** double free or corruption (!prev):
0x00002aaabc610420 ***" error which IMHO is a scurrilous lie ... I dont
see anything wrong with the code which has been working for a long
time.

Things are greatly complicated by the fact that the new machine is
AMD64, this software is a plugin loaded dynamically by (Sun) java so
gdb isnt an option I dont think, and that I am stuck with java version
1.5.

Im basically guessing at solutions and hoped others might like to guess
along with me. Ive tried

CC=/usr/bin/gcc-3.3 CXX=/usr/bin/g++-3.3 CPP=/usr/bin/cpp-3.3
CXXCPP=/usr/bin/cpp-3.3 ./configure

and the same with 3.4 but to no effect.

This is all very vague I know, but therein lies the challenge :) Any
suggestions?