My month old viera 46" plasma ( the one with freesat) has developed a fault about a week ago. When it is first switch on, there is a black moving interference over the normal picture which gets gradually better then disappears over about 20 minutes. Then it seems to be ok for the rest of the day.

I am not 100% sure, but the driver ribbons on plasmas are all on the edges. If you have a line in the center, it is the screen. I hate to say it, but it would seem like a defect or damage.

There are videos on YouTube on how to fix the black line problem on plasma TVs. There is specifically a nine year old boy named Nico that shows how the repair is done. It is a simple problem but time consuming because you have to take the back of the TV off and maybe two other large parts. The problem is caused by solder that separates or breaks and you just take a small tipped solder iron and reflow the solder. It might take someone that doesn't know much about TVs, a couple hours but it is fixable. There is an AV forum online that shows pictures and instructions on exactly how it done:
http://www.avforums.com/forums/plasma-tvs/462873-black-line-fault-hyundai-hpt4240-fixed.html
While the posts on this forum are old-most of the plasma TVs are basically the same as far as how to fix the problem. We're getting ready to takes ours apart because it has a black vertical line on the far left of the screen. Our problem started about a year-and-a-half ago but we've just been too busy to fix it but I'm tired of it so we'll try it.

hello, did you sort out the problem?

This is a fault developing within the screen, the only remedy is to have the screen replaced, there is no exact answer to why this has happened, it is just the nature of a plasma screens make-up that sometimes a fault can develop like this within the characteristics the display

Yes, the unit has a problem. I work for Panasonic in New Zealand and the unit needs to go in for servicing. 10 flashing lights means a fault has occurred (if I was at work I could tell you what 10 flashing lights means).it should be repairable.

Seems like a hardware problem. Something is probably overheating or something like that.

I would suggest either returning/exchanging the TV (2 wks is usually in most return policies) or if you can't do that, register your TV with panasonic. After registering, call them up for service covered by your 1 yr warranty.

I would use the warranty at Bestbuy at that point. Opening up the TV would most likely void the warranty.

It is very likely that cross talk does corrupt the link but for Panasonic to "blame" anyone else is not very professional. Anyway, if it worked for 6 months perhaps disconnecting the Foxtel IQ and reestablishing the Viera link with the Panasonic devices then reconnecting the Foxtel IQ for another 6 months of happy viewing. This is not a permanent solution but the alternative doesn't seem to be an option.

try upgrade.

Sadly, the plasma screen is failing. The green strip is no longer functioning properly and the failures will continue to progress.

If still under warranty, get it exchanged.