Comparing Signal Strength Issues on iPhone 4 and 3GS

Once the iPhone 4 was up and running it appeared call quality was worse in the house. There were a few drop calls and a few calls that did not go through when generally the iPhone 3GS was just fine. Observing the signal bars, it seemed that the iPhone 4 had some odd signal issues, but when comparing with the iPhone 3GS, it too seemed to exhibit odd behavior. Is this an unnoticed iPhone issue? An issue with iOS 4? AT&T?