Dropbox registry issue - any fixes?

Anyone here know how to PROPERLY fix a Dropbox error with message "unable to access vital account information" Windows registry error?

I have tried ver 1.1.45.exe and that worked for 10 minutes OK then the message reappeared. Uploaded 1.2.45.exe and that was worse. The Dropbox forums are full of people with the same issue. In the past 3 months I've deleted registry data, uninstalled and reinstalled umpteen versions and STILL it doesn't want to work on this WinXP SP2 PC.