Here's a bizzare bug, probably something Treo-specific: When I load Skype into the foreground, then pull another application (e.g. Pleco launched using PlecoLaunch) into the foreground (thus putting it in front of Skype), the little box that you tap to bring up the soft keyboard doesn't go away. Happens with Pleco when the main area is set to full-screen, but if I launch, say, the reader, it doesn't affect the reader, and when I close the reader, the little box has gone. Very odd, but easily fixed by minimising Skype before opening Pleco. The box will also disappear if I turn the screen off and then on again... But it stays if I minimise Pleco (via the OK hard key) then bring it to the foreground again. Also affects PI8, so it's not just a Pleco issue. Doesn't affect Skyfire or PocketTunes, but they both start full-screen.
A related issue is that, while the left and right soft keys vanish when the popup definition appears, the text entry button doesn't but instead obscures some of the information present at the bottom of the box. This only affects the larger of the two pop-up boxes, the Instant Access one.
Another minor, but weird, bug (again, probably a Treo-specific issue if it doesn't appear on other phones): Hitting the hardware Start Menu key does nothing when Pleco is in full-screen mode. I have this issue with other full-screen applications as well, *except* PocketTunes... Anyway, just something I figured I might as well bring to your attention.