[putting gdb-patches back, in case it's useful to someone else]

Steve,

> > What I will do as soon as I have a moment is double-check that I didn't
> > make a mistake somewhere, or forgot something. That would definitely
> > explain the problems you are having. We'll get to the bottom of this!

I tried taking a look at what might be causing you some trouble.
I can see some differences between our GDB and the FSF GDB, but
nothing like what you are seeing.

I did have a hard time getting libunwind to be activated, though,
and that failure is silently activated, or not.  That's why I took
the bull by the horn, and decided to make that unconditional:
http://www.sourceware.org/ml/gdb-patches/2011-06/msg00234.html

As I said before, the system libunwind is not performing as well
as GNU libunwind does. I use libunwind-0.98.5, not the latest
version. Either version will need to be patched, but I'm attaching
the patch I use with 0.98.5. I also sent some patches to the
libunwind mailing list for the HEAD, but I haven't had time
to test.

That's really as far as I can spend on this, as I've already spent
8 times the 2 hours I wanted to dedicate.  There are a few fixes
I should track down at some point that will further improve the
results. But at least I'm satisfied that I didn't miss anything
in my patches...

-- 
Joel