It would be nice to have a known issues page for bugs--and even nicer if there was a projected resolution date (if any) for them.
(This would probably be nice for all products, not just defraggler.)
I posted about Defraggler not working for 3TB drives:
http://forum.piriform.com/index.php?showtopic=36398
Someone mentioned that this had already been metioned a couple times. (Not sure why I missed it my search initially.)
http://forum.piriform.com/index.php?showtopic=34995
But rather than search the forums, a bugs page, or even a sticky on the bugs forum (which I did look for) would be handy.
Anyway, just a suggestion.