Metastability: yes, your absolutely right. I had this with a Microsoft Mouse. It was perfectly motionless, but the pointer drove over the screen until I touched it; this occured never before and never afterwards. Obviously they have no money for Agilent chips. Can't Metastability be avoided if you take a Schmitt Trigger 74HC14 with a small RC? This would still be cheaper (and smaller) than the Agilent chips. Besides I could also do a read of the state until its stable..

Werner