Problems activating XKB configuration

[Ruben Porras <nahoo82@telefonica.net>]

Hello, I've installed Sarge yesterday and updated GNOME using the
experimental repository, now, every time I log into GNOME it displays an
error:

Translating it into English, it says something like this:

Error activating the XKB configuration.
Probably it's an internal X server problem.

X server data:
The XFree86 Project, Inc
40300001
Using XFree 4.3.0.
...

And so on. It also asks to send the output of the following commands
with the report:

$ xprop -root | grep XKB
_XKB_RULES_NAMES_BACKUP(STRING) = "xfree86", "pc105", "es", "", ""
_XKB_RULES_NAMES(STRING) = "xfree86", "pc105", "es", "", ""
$ gconftool-2 -R /desktop/gnome/peripherals/keyboard/xkb
 layouts = [es  es]
 model = pc105
 overrideSettings = false
 options = []

It seems ok to my inexpert eyes. I'm not using reporbug because I don't
know which one is the offending package.