Originally posted by GunsForBucks:

Should be easy enough to verify. Hit esc and go into pause mode and see if your frost potion is timing down. It shouldn't if you play solo and not start a server.

If it does then you should probably run a file verify and remove all mods and check just to be sure and then submit a bug report in the sub forum if it still happens.

Sorry been asleep!! (yes this is the next step !! but dont need a frost potion per se.. just try jumping mid air then hit esc.. you should freeze mid air... if not file verify