Look at my last post.I edited it.
The cards you tested with (ati) run on the open source driver.If you would have used an ATI HD card I bet you would be booting into an black screen.This is because when you update to 9.10 it trys to use the xorg.conf file you had before.If you deleete the xorg.config file,and roll back to the mesa driver before you update you should be able to log in,because 9.10 will write an xorg,conf file for you...It doesn't overwrite the one you had.Hence the conflict it will have.
Iv'e even seen cases where This would happen to nvidia too,or any graphics...
Also OpenOffice will error if you upgrade...it wont load up the new language packages,or not all of them.
I suspect this is firefox's problem too...not overwriting the configuration.
Madwifi will not work also...It wont compile the new driver.It will try to use the driver on the new kernel.Which won't work.
Your screen shots tell me your using the open source driver...if in fact your using those drivers listed in synaptics.I haven't got around to those drivers yet...I'm still figuring out the new way Karmic deals with the xorg.conf file.Ill load em up here in a few days,and start hacking up the xorg.conf file,but I don't think it will be any better than the mesa driver.
Do you have an xorg.conf file in the x11 folder?I'm a betting man,and I bet you don't...I could be wrong tho.
If you did a clean install I'm sure you would not have one(I don't) I'm want to see if you upgrade if you still have one.