Troubles with OSX

Howdy all.

Recently I've been noticing an issue when running SmartEiffel
applications on OSX.  Namely, I've been getting EXC_BAD_ACCESS (SIGSEGV)
exceptions thrown.  This occurs for apps that I've written which tend to
use a reasonable amount of memory and I'm wondering if it's related to a
GC issue.  This issue hasn't occurred for any other OS I've used
(FreeBSD, Linux and Windows) when running the same applications.

This problem occurs under both Tiger and Leopard and for gcc 4.0.1 and 4.2.

I've tried to debug one of my apps using gdb but to be honest I don't
have much experience with this debugger and am not getting back too much
info (the routine it says where it's dying at is just an empty string).  
I've been able to reproduce the issue easily enough in one of my apps
and the Eiffel code where it's occurring seems harmless enough - it's
simply a reference equality check (I determined this using logging
statements).

Does anyone have any suggestions on how to go about tracking the root of
this problem down?  I've started to have a look at the GC code but I'd
like to know if I really need to look at this as I can see it might take
a bit of work to get up to speed with it.  :-)

Thanks in advance for any help.

Cheers.

Phil.