2 days ago i removed the protector i had installed after purchase as my n900 got unresponsive on touch pretty often. The effect was that it looked like the device did not recognize the release of the touch or that it received another touch event from anothe location of the screen. After the effect remained over a reflash with the original firmware, I suspected the screen protector and removed it and the problem immediatly vanished. Also the effect had only appeared approx 2 month after the protector got installed, so in case anyone here has similar issues, maybe remove the protector before reflashing the unit. I don't have the brand of the protector at hand but will add that info if i should still have the packaging.

Edit: The packaging of the original and problemativ protector is already gone, I only kept the two additional protectors in it. However my new one which seesm to work petty fine and was easy to install is froma company called displex (www.displex.com). Note: I live in germany, so no idea if this brand is just a rebrand of some other protector for the local market or if it's a real manufacturer.