Various applications give GDK warnings on the commandline:
(thunderbird-bin:4876): Gdk-WARNING **: gdk_property_get(): length value has wrapped in calculation (did you pass G_MAXLONG?)
The same in Firefox and some other applications. It isn't really a problem but it's just annoying..
Is there something to do about this?
Yup, bug the upstream firefox/thunderbird programmers about the issue
recompile might help, but I am not sure for that.
I get these warnings from about half of all graphical apps... They seem to be harmless.
This has been changed in the latest gtk update. Many programs supply this wrong value. With the new gtk, a new piece of code is inserted into GDK which fixes some bugs. However, this piece of code is incompatible with the way some programs use GDK. When GDK detects this, it prints the warning you get and reverts to the old "wrong" style.