the karma function should only be visible for other form users & not yourself...it stops you giving yourself karma points by the dozen ;D feel free to share with others though!!
Still cant give anyone else it? I've logged out and in? Maybe its a profile setting ,I'll go and investigate.
Do you have to have posted a certain amount of times (i.e. over 10) before you can give karma? For some reason that rings a bell but I might be making it up