Hi Fredster,
Your cooking the mugs far too long :) you want to be using anywhere between 160 - 180 degrees and 180 seconds. Warm the press up with a knackered mug in, when it gets to temp whack a mug in with your paper taped tightly, give it 180 seconds. Once timer goes off take mug out, replace the knackered mug in the press and turn off. Take paper off immediately and cool by dunking in warm water or with a cool fan. You shouldn't feel any of the print, or paper, as the ink has sublimated into the coating on the mug, not the surface. thats why its called sublimation.
Just to be certain - you are using sublimation ink aren't you?
Cheers John