amd64 floating point context save/restore changed?

Has there been any changes within the last couple of days that could
affect context save/restore of the FPU on amd64?  I am getting
consistent SIGFPE signals in an application I built.  The problem is, if
I just rearrange the code a little bit I can get it to move.  Since it
is consistent for any particular version, I would guess it to be related
to pthreads if it is context save/restore.  In both cases I've looked at
there was no reason the SIGPFE should have occurred and, in fact, does
not when the code is reordered.

I can flood the list with a lot of backtrace info, but prefer to send it
to whomever is working this area to save others.

Sean