sometimes when tilt sleeps, it wont wake?

When I had the first three phones I was just typical "Joe Consumer" I had no idea about this website or any of the cool stuff I have learned here. So consequently I just knew there as a problem and it was pissing me off so I kept taking them back and swapping. If the 4th didn't work I was going to go with the iphone so I could have something to use when I travel to check email and other BS. But the 4th worked and all is well. Although sometimes i wish I would of got the Iphone just because of battery life and it is alot faster with applications than my phone at least. But I cant take that feeling of being in a Jail Cell every time I hold that thing...........