Bugs that are really annoying:
- Some windows minimize towards the center of the desktop rather than towards the task bar. Qt Creator and tvtime always trigger that bug here.
- KWin is very slow and choppy with low power GPU modes (50Mhz graphics / 135Mhz mem / 101Mhz proc). So I have to force a higher performance level.
- Icons "jump" around when hovering the mouse over them (Desktop as well as in Dolphin). Doesn't always happen. Whether it happens or not seems to be fixed at login time.
- Switching keyboard layout ignores the desktop (the desktop will use the last layout of the last application.)
- KMix lacks some mixer sliders offered to me by alsamixer. Namely the "front", "rear", "center", "woofer" and "side" sliders. Only "master" is offered. This is with an Asus Xonar D1 card.
- KDM stopped remembering the user name of the last logged in user after 4.6.
- Admin password prompts are in stealth mode. Practically, you wait for a long time for the button you just clicked to do something, only to discover that this whole time a password prompt was opened that is hidden behind the current window.
- Even though I set KDE to always automount new devices when I plug them in, it doesn't work with everything; I still have to click on "mount" in the plasma notifier.
- The "back" and "forward" buttons of my mice (all of them) don't work. No going back/forward with them in stuff like Konqueror, Dolphin or file dialogs.
There are other smaller annoyances, but they're simply due to broken design rather than being bugs (for example the resize handle on borderless windows sometimes cover scrollbar buttons and statusbar information.)
I still like KDE very much :-) It's just these things get very annoying and it's very disappointing every time I update my KDE installation and see they haven't been addressed. (I did report them on bugs.kde.org of course.)