I have a quickmount4 as well.
Had the same problem with reverse wound laminate.
After I finished a roll, I switched to a non-reversed roll and more problems with laminate not separating from backing.
I called NY, they were very helpful.
They sent me the lockdown kit and a new belt.
If you use primarily reverse wound material, the belt will stretch to accommodate the twist.
If you use the same belt for a regular wound roll, it will slip.
After receiving the kit and belt, all has worked fine...
Except when I laminated the lint free cloth, but thats another story