With SP1, Outlook 2003 stopped running rules on emails that were determined to be spam, http://support.microsoft.com/?kbid=842510#XSLTH3133121121120121120120. Is there anyway I can have the rules run again? If not, how do I uninstall SP1?

Thanks.

I've been having a look into this issue.
If you go into your rules one of the options on the top is rerun rule.
This will give you a pop up where you can select which rules to rerun.
If this is a specific problem with sp1, it may be a case of just review your rules, possibly re-entering them and then applying again.
Hope this helps I'll do some more research tomorrow once I get into the office.