This will be my final post since my HD80 is now dead.
To summarize my experiences:
I was not able to solve the problem with the dust blob (see my post #3457). I tried the air-can technique, but to no avail. Whatever the blob is, it is stuck on the DLP panel and appears to be affecting the rest of that column.
I had also sent the projector back to Optoma service 3 times (once for the main board, once of just some video modes failing, and once for the ballast (which they claimed was the bulb).
I'm now on my 4th bulb. I got the bulb+reflector units from www.purelandsupply.com
(#69508) and the installation is easy. Cost is $227 + S/H. In total, there are only about 4000 hours on the unit. And none of the bulbs actually failed. It was always that stupid red lamp light.
My final problem is that I suspect that my lamp ballast has completely failed; and I've probably had this problem for awhile. The unit comes on, then a minute or two later the picture disappears and the red lamp light comes on. The bulb itself is fine (as have been the last couple). It isn't the bulbs, its the ballast (or something else).
Although this is my 4th bulb, I know that the problem isn't the bulb. In each case, the bulb worked fine right up until the red lamp light comes on. If I power down, unplug, wait, etc, I could get it to come back on for a few days (but not anymore). I know what a non-functioning bulb looks like. I suspect that all of the bulb problems that people have been having are actually due to this other problem.
I also read that the Vivitek 5080 projector is made on the same assembly line as Optoma. I definitely won't be buying one of those either.
So my old Sharp Notevision7 (1024x768) is coming back out from the box in the garage. I'll make due with that until Epson's 21000 is available (they appear to be struggling with their new panel). The Notevision7 was an OK unit, and replacing it with the Optoma was a big $$$ mistake. I should have gone with a real company.
Ordinarily, I'd get the Epson 8700, but I can't bring myself to buy a 2D projector when good 3D is right around the corner. I've also read that Panasonic uses Epson's panels; so the wait appears to be the same for both.