inconsistent Permalink cgi error

My “pretty” permalink structure works on some categories and not others. WHY? I have beaten my head against a wall all day trying to find out the reason.

Example 1) These permalinks work correctly:

• http://www.toddolivas.com/blog/index.php/category/where-are-the-legal-secretaries-series

http://www.toddolivas.com/blog/index.php/category/paralegals-legal-secretaries123

Example 2: These do not work correctly. (Throws CGI error)

• http://www.toddolivas.com/blog/index.php/category/ccls-slug
• http://www.toddolivas.com/blog/index.php/category/computers

I can’t figure out why some category permalinks work correctly and others do not. There is no apparent different in the Manage/Categoris admin console.

Please help!

Thanks,

Todd Olivas