This might be of help:

I wanted to upgrade my Dell Studio 1749 to 11.04 via a fresh install.

But, I could not for the life of me figure out why the Natty 11.04 Live CD would not boot on my Dell Studio 1749.

32 bit, 64 bit, alternate CD, nothing worked. I eventually upgraded to 11.04 from within 10.10 (64 bit). The upgrade installation completed without errors, but tragedy struck again, after a reboot I could not boot the 2.8.38 kernel!

Long story short: THIS IS THE SOLUTION:
The Dell Studio had the A05 BIOS installed. I upgraded to the A08 BIOS and now everything works!