There are currently two different audio/video issues that Verizon has admitted to and acknowledge.
The first is the issue with the HDMI handshake between Motorola and Samsung. This one Samsung has stated that it affects model years 2006-2008. Pre-2006 and post-2008 should not have handshake problem. This is where the pic/audio drop out completely and do not return unless the HDMI cable is disconnected/reconnected or the STB is rebooted. The TV will usually display "unusable signal" or something to that effect. Motorola and Samsung have been working together to correct this and supposedly found a solution which Verizon is supposed to roll out in the near future. From what I heard, tentatively for the end of this month.
The Second issue affects multiple TV Manufactures. This is where the screen will go pink or green. (from the sounds of things this is the one that this thread started on). This is similar to the handshake issue but has more to do with a mis-communication rather than no communication like the handshake. This is supposed to be address at the same time as the Samsung issue with the rollout. This one has more to do with the 7xxxx series boxes (although it does happen with the 6xxxx too, just not as common). It has to do with the way the 7xxxx boxes use a removable program card rather than an internal chip.
Both issues can be resolved by changing to component cables rather than HDMI.
Any audio or video drop outs using any cable other than HDMI, are not "official" known issues and are dealt with on a case by case basis (according to my buddy at Verizon)
Has FIOS come up with any solutions to the drop out problem associated with the HDMI interface? I know it's an old problem and I wonder if they are trying to fix it or hope everyone forgets about it. Maybe Cablevision should mention the problem in their ads when they compare their service to that of Verizon.