After installing 3.5.0 RPMs on Mandriva 2010.2 with KDE 4.5.5, I realised that LibO 3.5.0 does not use the system's GTK+ style, but its own, which is ugly and looks like Win95. This used to work in 3.4.5 (and still does after going back to 3.4.5).
Thanks for bugreport
Please, verify if in last version of LibreOffice still reproducible
(3.5.3 or more new)
Thanks for answering!
After having used 3.4 for a while now I retested and found out that the issue is still there in 3.5.3, but after some trying around I found out that it's not a program bug - it's a component I didn't install. Installing gnome-integration (although being on KDE) cured the problem. Did some GTK2-components move from some core package into gnome-integration? In 3.4, things worked nicely on KDE without the gnome-integration package. Maybe one should keep a functioning GTK2 integration even without having to install gnome-integration if GNOME's not used...
Nevertheless, problem solved for me :)
Thanks for additional testing
Due to last comment, changing status to WorksForMe
If problem will appear again, please, change status to Reopened