Hi,
I just received a couple of weeks ago my new UM2 Extended and I must say I'm very impressed.
The glass which was delivered with the heated bed held the parts in place like a charm and seemed to be dead flat compared to my other 3d printer. Nevertheless that stickness seemed to be lost now for a reason which I haven't been able yet to tackle down.
Has the glass on the heated bed a special coating applied which might have been rubbed off during cleaning? The parts always used to stick on the glass and I haven't been able to pull them off until I was soaking the glass in cold water together with my 3d printed part. Then it popped off out of a sudden.
What can I do to get this impressive behavior back?