Mine shows zero to one bar quite often, yet I can make/receive calls. My BB shows a lot more bars all the time and in the same spots as the Bionic that shows zero/one. without moving the Bionic it will sometimes jump to 3-4 bars. It seems schizophrenic.
Update: I'm now seeing that it is showing the same or 1 bar more then the Droid x in 3g. But if it goes to 4g it drops way down to a couple less then the X.