Back in Dec I replaced my TV with a new Sony Bravia LCD. Ever since, every once in a while, the TV picture tiles or freezes for 1-2 seconds. When it comes back, the picture and voice are out of sync. To get back in sync, I have to turn TV box off and on again. I contacted Sony and they sent me a software patch but told me they had not heard of similar reports of freezing pictures. When the patch failed I called Verizon and they swapped the HD/DVR box. Still no resolution. I have another TV (non-HD) on a FIOS box and occasionally it freezes too. Am I alone in experiencing this problem? Seems like its a FIOS issue not a TV issue.
You may want to check your signal levels to both boxes. Go to menu/customer support/in home agent, then choose the network diagnostics. After the diagnostic has ran. Press the blue info button. You will see the signal level at the bottom middle of the TV screen. Look for something like SNR Value. It should be around 32-38 Db. Check both boxes. If it is low, then you have a poor coax signal to the box. The issue possibly would be from the box out. Hope that help you.
if you are experiencing channel freezing on multiple boxes it could also be poor signal strength at the splitter. easiest way to find that is to start at the cable box and work backwards until you find it. resetting all connections there should help with the issue