[Tommy turns off optimization, and all is well]
Do either of these blow up too?
4 * 0.60653065971263342 4.0 * math.exp(-0.5)
yup.
OK. Does the first one blow up? Does the second one blow up? Or do both blow up? Fourth question: does
4.0 * 0.60653065971263342
blow up?
... And the next step is... ?
Stop making me pull your teeth <wink>. I'm trying to narrow down where it's screwing up. At worst, then, you can disable optimization only for that particular file, and create a tiny bug case to send off to SGI World Headquarters so they fix this someday. At best, perhaps a tiny bit of code rearrangement will unstick your compiler (I'm good at guessing what might work in that respect, but need to narrow it down to a single function within Python first), and I can check that in for 2.1.