Comment 1 for bug 721198

I agree with you. Someone already report such a bug.
The problem is due to the way that java-gnome is handling warning from the gtk+ native library.

In few words, java-gnome considers as an error the warning of gtk+.
Is it a wrong behavior? I don't know but it should be discussed.

The problem would not appear if this long time bug would have been resolved.
https://bugzilla.gnome.org/show_bug.cgi?id=305325