How long have they been sticking? I have one of these and have not been impressed. I would not buy another, but that's just my $.02 based on how much they cost. Mine won't hold on for more than a few days. I guess they are good if you keep sticking/removing between trips.
I would imagine the temperature they are used in has alot to do with how well they hold. I know the gps in my car doesnt hold as well when its cold out as when its 90 degrees.
Brad
I notice that it won't stick for too long on the non-skid. However, Might work better on the NS if I wet the suction cup per the directions.
Works great on smooth surfaces though.