GTK and appls

[szanelli <szanelli ngi it>]

Hi guys,
I'm new for this mailing list so, pls, be patient since I'm not expert 
with GTK an english is not my mother tongue. :-)

I'm running Ubuntu Feisty updated every day via apt-get or update-manager.

I'm facing problem with xmms and other appls such as the management of 
the bookmarks in firefox/swiftfox.
Running xmms I get following error

===================================================================
Gtk-WARNING **: Unable to locate loadable module in module_path: 
"libqtpixmap.so",
===================================================================

while running bookmark manager in firefox/swiftfox i get

====================================================================
(Gecko:21456): Gtk-CRITICAL **: gtk_drag_get_data: assertion 
`GTK_IS_WIDGET (widget)' failed
====================================================================

I get other errors running appls which use GTK, but I don'remember :(

I suppose GTK is broken, I'ld like to remove and reinstall it, but I 
don't know what to remove without damaging the whole system.

Can you help me?

Thank you in advance