"Save As..." dialog freezes applications

[Pieter Barendrecht]

Hi,

All of a sudden, I'm unable to save files with the "Save As..." dialog.
I tested with Chromium, Firefox, and GIMP and all have the same
problem. For some strange reason, I can save PNG images with Chromium,
but no JPEG images.
When I click the "Save As..." function, the dialog appears but freezes
instantaneously. 

Not entirely sure whether this is XFCE-related (if not, it should be
GTK right?).

By the way, where can I find the log file(s) from xfce4-session?

Regards,
Pieter