Problem with exception handling on x86 / am using "as" version 2.9.1

[pnr@wxs.nl]

I am struggling with exception handling not working as I expect
it to. Code seems to throw okay, but falls through all catch
clauses (including '...') and ends up in the library abort
routine. Alas, I can't get the problem to reproduce in a simple
demo program.

1. Is this a known problem ??

2. I want to step through the stack unwinding process in detail.
Where do I find documentation on how g++ does stack unwinding
precisely (catch stack frame layouts, algorithms, etc.) ??

Thank you for your help!

Paul