Installing Ubuntu Feisty Fawn on Mac 2 x 3 GHz Dual Core Xeon

[William Clapham]

I tried to install Feisty Fawn 7.04 on my Intel Mac following instructions
provided in the Simplehelp tutorial.  I got as far as the boot stage and
receieved the error message:  Your CPU does not support long mode. Use a
32bit distribution.  I am a newbie.  Can someone advise me what to do next?

Thanks in advance.

Bill