Photomerge Crashing (CS3)

I am trying to stitch a small panorama in CS3 from 4 16b ProPhoto RGB TIFs. The TIFs are simply four shots which should combined into one long horizontal shot. Unfortunately, if I merge to panorama from LR2 or just from TIFs exported from LR2, then PS3 crashes after working for about 4min or so.

I'm tempted to buy ptgui since it handles them fine and I've encountered this problem with photomerge with a number of panos I've tried to stitch. Does anyone have any advice about how I could prevent these crashes?

Thanks!

PS. This is the 32-bit windows vista version. Thanks!

I am having this problem as well on one machine out of 6, anyone know anything

I ended up upgrading to PTgui which turns out to be much faster and completely reliable, though a bit pricey considering I was expecting Photomerge to already work. That said, it offers much more precise control in a very unobtrusive way so in the long run it was probably a good way to go.