What OS are you running? What version of PS? Have you updated to the latest release? Also, what language and keyboard are you using? What hardware are you running? Are you using a tablet? Have you enabled any apps which monitor or manage keyboard shortcuts?
figured out the problem.... apparently my english version was actually some sort of indian version of english or something like that so as long as i change the keyboard to that specific language setup (even if just while im using photoshop), shortcuts work just fine :D