Anyone know anything about SEO?

[king arthur]

Sometime around the middle of last month, I installed a script to count the click throughs on one of my sites, so I could monitor which links and banners people were clicking on. Each link now goes to a script called click.php which gets the destination in the query string, and stores it along with time etc. in a database, and then redirects the user to that destination using a header redirect.

Starting sometime towards the end of last month, I notice I wasn't getting very many hits from Google. In fact it seems that I now get no hits at all from Google aside from ones where people have actually typed the URL into the search bar.

I'm wondering if the two are related? I know Google doesn't like blind redirects, but this script is harmless.

If this is the problem, how would I go about fixing it? Can I put something in the header to tell search engines what I am doing with the redirect? Or do I put something in the robots.txt file to tell Google not to follow any links with click.php?blahblahblah in them? I can't believe something like this would piss Google off so much that it stops sending me any hits at all - up to that point I had about 70 or 80 hits during July from Google in its various incarnations - but I can't think of anything else I've done which would cause the problem.