iMac will not boot Ubuntu 11.04 from LiveCD

[Andrew562]

I have created two live cds of the newest Ubuntu release (32 and 64) and I have been able to run the live cd with no problem on a PC. However, when I attempt to boot the the live cd in my iMac, the cd will hang at a black screen with a white blinking cursor. I was able to boot from an old Xubuntu live cd (9.10) with no problem at all.
Has anyone else had this problem and know a fix?

I just realized that the new live cds I created are on a different brand of cd than the old one. Since the newer live cds work on my work PC, I am going to assume that the iMac's dvd drive might just be picky.