When screen is locked, screensaved doesn't start, instead - screen becomes black, after what there is no way to get to desktop - only relogin helps. This is already reported on forums, but i did not see any report about it there (mostly was caused by oxygen transparent). Ttransparency causes freezing not always - transparent bespin with disabled blur doesn't trigger problem. Qtcurve with 100% opacity doesn't cause problem as well. Disabling of blur kwin effect with transparent qtcurve doesn't help however. Reproducible: Always
Don't think this is kwin's problem. I've noticed this problem in QtCurve recently but don't know what to do about it yet. Related bug: https://bugs.kde.org/show_bug.cgi?id=312425 https://bugs.kde.org/show_bug.cgi?id=311574 https://bugs.kde.org/show_bug.cgi?id=314663 (probably duplicated)
"kscreenlocker" &"kscreenlocker_greet" processes are hardcoded to skip ARGB in bespin. KWin is completely unrelated here - it's between styles and the screensaver (fiddling areound with the window, resp. not catching that) *** This bug has been marked as a duplicate of bug 314663 ***
@Nikita Zlobin (I thought said this somewhere else but cannot find it...) In QtCurve you can also blacklist those processes. I haven't tested myself but it should work.
@Thomas Do not set to ARGB when a window already exist and when X11BypassWindowManagerHint is set seems to help. And we probably don't want translucency on such a window anyway.