Error message meaning
 

I finally got Ubuntu up and working but could not get higher screen resolution on the LG card. So, I changed the card for an ATI card. Then (and now after replacing the LG card) I got several lines of error messages like:
[ 76.128533] Ext3-fs error (device sda5): ext3_get_inde_loc: unable to read inode block - inode=7462931 block=29851650.
And the screen freezes up.

As a newbie, I don't have a clue what this means or what has happened.
My first thought was to re-install Ubuntu, but if this is a hardware problem, I do not know how to procede.

Direction please!
Wayne

This is an error related to the hard disk, not to the video card. Ext3-fs error (sda5) means error of the ext3 filesystem on the fifth partition of the first disk. The first thing you can do is to run a diagnostic tool for the hard drive. Try to get the proper one on the manifacturer's website. If the disk is damaged, most likely you have to change it.

In any case, do a backup of your evaluable data on some external device. Always. :)