You have yet to show that overclocking affects refresh rates.
You have not shown that running the card out of spec does NOT affect refresh rates. You can't put the burden of proof on others, you are the one making the claim that it absolutely DOESN'T, other people are just saying it COULD have in impact, and the only way to determine that impact is to collect ALL the information, seemingly important or not.
There should be a survey - but is should collect all information, including:
windows version
windows service packs installed
directx version
PREVIOUS directx version (whether you went from 8.1 to 9.0, or 8.1 to 9.0b, etc)
current video driver version (omega or ATI)
previous video driver version
other installed components and their driver version
basic system config (motherboard, RAM, etc)
installed tweaking/overclocking/general system utilities/software
and card overclock/mod status.
I'm sure there are things I missed...
The key is to find something common to all people who had lost monitors, if in the end the only commonality is using the 3.8 driver, then that is telling, but if there is another common factor, then that has to be investigated.
Also, you had know there was a risk when you overclocked your card, or put a barton heatsink on it. As soon as you did those things you had to know you were operating outside ATIs specifications and, therefore, warranty protection. You have to know that ATI cannot test every card in every out of spec condition, so they don't know if running a card in that state will cause a problem or not and neither do you.