[HELP] Category 404 Error!

Hello, i am not sure whats happening but today, when i created a new category as usual, it shows a 404 page! Whats going on? i created a category called Technical Support and my site shows as http://mydomain.com/technical-support/ its logically correct but i get a 404 when going to it… I need a category to show all my articles but my articles works fine except to the archives category link specified…

Please help me thanks.