Could have saved yourself the wasted time if you'd taken my suggestion back in post #2, which is exactly what you've just done, only 5 days later.I have already reformatted the TM disk and it works fine. I copied the files to a older disk as it's still readable and can be used. So no disaster, just a lot of time spent on this problem.
Thanks for the help guys!
... Sounds like Windows supports standard solution. "Reformat" I prefer to try to solve the problem with a minimal damage first. Thats just how I am.