You know;
I know this is an unenlightened response, but sometimes it's easier than de bugging.
I would apt-get purge the gnome packages you have installed (purge removes config files too) and then apt-get install the gnome-core package mentioned earlier; which should install and config x as well.
Only thing that I would watch is when you issue the purge command and see what's to be removed, I have seen apt totally thrash entire systems removing dependences and such on major system components. Should be fine, but be aware of what the system is doing
Hope it's helpful;
TeddyB