Here's the run down.
My graphics card is an older 64-MB AGP, Radeon 9000 (RV250).
I tried to install 11.04 on a clean HD after I burned the iso image and copied it to CD with Infrarecorder. That got me no where except to the “oversize recommend mode 1280x1024” error and then my monitor turned off.
I then downloaded and burned a copy of the alternate iso and used it to install. Got to the same place as above. The next time I tried to install from the alternate CD I pressed the 'shift' key which dumped me to a screen where I could choose: “Run Ubuntu with Linux 220.127.116.11-generic (recovery mode)” which I chose.
From there I ended up at a menu of several choices of which I chose: “Run Ubuntu in low-graphics mode for just one session”. There was also an option to reconfigure my graphics card at this menu. But that is a dead end. When I choose it I get right back to that menu.
So I am booted into and running 11.04 in recovery/low graphics mode. I have my wireless running and have been able to 'reload' the Ubuntu packages thereby getting them up to date. In fact I'm posting this from Ubuntu/Firefox.
What I don't know how to do is check and, if necessary, change the driver for my graphics card.
Would appreciate a 'nudge' in the right direction or, with these symptoms, where to enter into your excellent flowchart.