I can get them to work again by powering off but its annoying and reminds me of blackberry. Any ideas
I have noticed that at times also. Another thing is that the home screen loses all icons. When this happens hit menu...settings...applications...manage applications...then hit menu again...filter...choose running....scroll down to HOME...Hit Force stop.
It sounds like a lot, but it is much faster than turning off the phone and on again. Hope this helps!