It sounds like either a) you've been playing in the activations tab entering wrong strings or b) the card has somehow become corrupt. I very much doubt the second option though, as the card probably wouldn't work at all.
Either way, contact your reseller who should be able to help you out. There's nothing that can be done by posting here on the fourm.
Also the "someone has tampered with time" error message means you've (at some stage) set the clock on your PC incorrectly.