Search engine spidering urls incorrectly

Hi,

I have been getting alot of referals from search engines who have indexed some of my site's urls incorrectly.

For example:
www.domain.com/?t=859&page=2

When I go there, it doesn't redirect but goes to the homepage.

that topic was created 2 weeks ago. What is the cause of this problem?

It worries me that it's not only restricted to one url but most of my referrers.

When I check the source (search engine) of the referrer, it lists that format of the url.

I am using httpd.conf, so should I add:
RewriteCond %{QUERY_STRING} ^t=([0-9]+)
RewriteRule ^$ showthread.php?%{QUERY_STRING}

for httpd.conf? or does it have a different format.

Hi,

Thanks for the code.

It works now fully and after implementing that code, I am not getting any incorrect urls anymore.

Thanks