[CentOS] Welcome screen is crashing.

Hmm... it was tough to get into CentOS this morning. I booted up, and 
after the screen flickered a bit, I got an error message that said some 
png file couldn't be found (Sorry I was in a bit of a panic and didn't 
think to copy down the whole error message verbatum). I think it was 
"throbbing.png", which is a little salacious sounding, but that's what 
it was.

Anyway, it says this image can't be found, and there's nothing else on 
the screen but the error message and a button to click "OK". So I click 
it, and nothing happens. Ever. No matter how many times I say Okay, it 
just sits there.
So I tried restarting X, using my newly learned ctrl-alt-backspace key 
sequence. When X comes back, same message. Because I can't think of 
anything else to do, I try ctrl-alt-backspace a bunch of times in a row, 
and then after a few times, the error message changes. It says "X seems 
to be crashing. I will try to restart with a different greeting screen". 
Fine by me, so I click "OK", and I get this really plain, light blue and 
grey login screen. I login with my usual personal account, and I'm in.

I don't want to go through *that* again. But I'm not sure what the issue 
is. I was doing two things last night. One is install OpenOffice Beta, 
which, after help from this list, finally worked. I was also wanting to 
install new themes for KDE, but that didn't get far as I downloaded one 
theme, and I couldn't get past the ./configure part because I didn't 
specify the right perameters or something. But in the process of trying 
to figure out why the ./configure failed, I attempted to update KDE 
following instructions on their web site. Part of the exercise was to 
get qt installed, as the theme seemed to require it. But all I did was 
add a repository from the KDE site and do a um install of some KDE 
related programs.

There is one other thing that I notice about my system that's different. 
In the top left hand of my screen, on my panel, the CentOS logo is gone, 
and in it's place is the icon for a "Prominent North American Linux 
Distributor". Where'd *that* come from?

Dave