Don - thanks for posting all of the information on insurance. I will definitely look into that. As for
I'd like to know how the freezing caused the flooding, but ok
here's what happened. I was using the camera while snorkeling at Lauderdale by the Sea. We were seeing some great stuff that day - including a Spotted Eagle Ray! - but the camera froze up and would not respond to any button pushing. Since I really did not want to miss any more shots, I opened up the housing, took the battery out and put it back in, and went back in the water. In the process, I must have let a grain of sand in the seal because it flooded instantly - only a few drops, but enough to ruin the camera. So, yes it was my fault for opening the housing, but if the camera didn't lock up regularly I would not have had to open it. That problem (and the short battery life) is why I stopped taking it on dive boats.
I've looked into the Vivitars, but I think there is a run on them now as peoples' DC500s are dying. I'll keep looking, but eventually I'll probably sell off the housing, wide angle lens, flash, etc.
It looks like the Canon program has changed, but at least they are trying to build brand loyalty and keep the customers they already have!