Hello again,
I read your comments regarding this issue in my screen burn thread but thought i would reply here as you have started a new thread regarding this new issue with your G20.
If the coating was damaged when the set was in for repair then the repair agent is liable for any repair and you should contact them to report damage to your tv during repair, they are insured and the damage should be put right free of charge. If the coating has simply started to fail then it is covered by the warranty, there is no disclaimer that i can remember seeing when i read (several times) the warranty for my G20 when i had it.
Any damage to the coating should be repaired free of charge by Panasonic as the tv is within it's first year warranty, it may be a good idea to follow up your email with a call to Panasonic to get things rolling regarding repair...the only problem is that you will probably have to use the same repair agent as last time.
Sorry to hear you are having yet another issue with your G20, you truly have my sympathies, if it was me i would get the coating issue repaired and then cut my losses and try to sell the tv to get something else.