I wish I had seen this earlier. Sticking in molds is caused by lack of acid produciton on the surface which leads to knitting and toughening of the rind. If the pH isn't low enough, it will stick. The solution, as sailor pointed out, is frequent flipping. This will only occur with some cheeses though. Cheddar won't be an issue as the surface PH is already quite low. This is the reason pre-soaking in whey works, it speeds the acifdification on the surface. No offense, but Peter Dixon, as is often the case, is way off. If pressure caused sticking, swiss would stick like crazy in kadovas. If overacidication was the problem, per Ricki Carrol, cheddar would stick.
Good luck.