tedster - 7:15 am on Feb 22, 2010 (gmt 0)
This usually means someone is linking to your pages with that query string - as a kind of log file spam or part of some other more aggressive spam scheme. Yes, it "might" be a sign of something that is hurting your rankings.
Do you have a Webmaster Tools Account? If so you may be able to see such a page referenced in your backlinks list.
I'd be very tempted to make these query string urls go 404, instead of trying to squeeze some link juice out of the them with a 301 redirect. If there are backlink pages (and I'm pretty sure there are) you may be better off without their vote for your page.
I'd also check a couple other things:
- Make sure these requests are really googlebot - reference [webmasterworld.com...]
- Use the "Fetch as googlebot" utility in WMT to be sure that these pages aren't hosting some cloaked, parasite content