I've been running gpc version 2.0 on my linux 2.0.x machines without any problems. Recently we upgraded some of them to linux 2.2.0-pre4. Now, simple arithmetic assignments cause segmentation violations.
I have no quick idea where this problem comes from, but before really tracking down the bug, I suggest to upgrade your GPC to gpc-19990118, our latest beta release which fixes many known problems in gpc-2.0
Peter