Re: Special window/application settings don't work anymore since Qt 4.8.1
I can only say that I have encountered that, too.
I know that we are in the middle of KDE rebuild/transaction (and newer python-
qt4 causes plasma desktop to segfault), so it may be matter of waiting until
all packages are rebuilt and uploaded.
Although I am no Debian Developer, I can only suggest to wait some time - if
problem won't "magically" disappear in next few days, then it might be good
idea to file a bug report - against kwin, perhaps (as kwin is responsible for
visibility of window decorations).
Ps. Didn't you send the same message on 10 May?