Googlebot mod_rewrite eliminate “?cat=23” at the end of url

Hello,

is it possible to write some additional rule for mod_rewrite
to eliminate “?cat=23” from post url’s, example:

you can reach one of my post entering such url’s:
http://videotrip.eu/category/ships/?cat=23
http://videotrip.eu/category/ships/?cat=233
…
http://videotrip.eu/category/ships/?cat=2333333

It’s a problem with googlebot – it visits many of my sites and ads “?cat=5”, “?cat=55” to many of my post’s urls. I have no idea, why googlebot gets such urls (any ideas?)

Additionally when using wp-cache plugin, all such pages are cached, so one entry can be cached at 2-3 different urls.

Is it possible to write some mod_rewrite rule to redirect all requests to proper url, I mean:

redirect (for example)

http://videotrip.eu/category/ships/?cat=2333333
to
http://videotrip.eu/category/ships/

Have you noticed such googlebot behaviour?

Daniel