Have used this for years now, on Vista and now Win 7, and it's great the way you can click on the internal pop-up control bar to bring a picture up full-size. (Not the external gadget option to show Larger size).
But a few weeks ago, for no reason that I know of, it stopped giving the full-size version when clicked. Delete, re-install, a couple of times, zilch. I wasn't happy, and my wife started complaining, as we both use this feature quite often.
Today I came across this link in the "Don't Panic" bit of Saturday's Times "In Gear". Looked into it, read the program's Help, and ran it.
It ploughed through the verification phase of "scannow" and reported "No fault found". So it didn't go to the fix phase. But the feature now works!