I have used a rewritten url for my jump links - I was rewriting all my dynamic links at the time. However, I did come across the problem a couple of times where my site appeared in Google as the rewritten static jump link in the url linking to another site. At the same time the actual site link disappeared from Google and, as you can imagine the site's owners were not happy. Luckily Google seemed to revert to the site's url quite quickly in both cases.

This situation has only happened (so far) with my static rewritten urls and never with the jump.cgi link - not sure what to conclude from that as I know that php dynamic links are a problem.

It would be great if there was a solution to this as it could potentially lead to legal problems as well as Google issues. I can't understand why Google hasn't fixed this yet as they have known about it for a long time.