Come on, you ought to know better by now: what version of Lazarus/FPC built for which widget set, what display manager (AKA desktop environment) and (to a lesser extent) what distro?
I think those are the important things. I don't specifically recognise the problems you mention but I'm running KDE with stuff including the IDE typically compiled for gtk2... there's a possibility you've got some different combination or at least some different underlying libraries.
MarkMLl