This is a recurring problem with 2 brand new sets of the 42LW5700 42" Cinema 3D SMART TV. The original TV started exhibiting "symptoms" about 3 days into ownership. I had it exchanged for another brand new set, and that's giving the same sort of problems 1 day into ownership.
Description of problem:
Intermittent. When TV is switched on (from standby mode), the interface is *very* laggy. When the volume on the remote control is triggered, it takes a few seconds (no exaggeration) for the annunciator graphic to appear on the TV screen. Volume up/down similarly takes a while for the graphic to update on screen. Picture on screen becomes "jittery". All controls slow down, and TV shortly turns itself off, then on again (sort of a reboot).
As mentioned, this is an intermittent problem. Often, after exhibiting these symptoms, when the TV is turned off (back to standby mode) and switched on again, no further issues result. Then they come back at a later time.
TV has been connected to the Net, and has updated itself immediately after installation. No further updates available at present. I don't know if the problem would have been present *before* the firmware update, since TV updated itself immediately after installation, and the problems manifested after that. In other words, it's difficult to tell if it's a hardware or firmware issue.
This has happened with 2 brand-new TV sets. I think I'm out of exchanges

, but I don't know if there's any point, since this appears to be a batch-related issue.

Please advise.