x86_64 oddities...

[whatsizbucket at comcast.net]

I'm a bit new to the 64-bit architecture.  I was under the impression that the 3.2+ line of Sempron's was 64-bit, but when I tried the install of the x86_64 DVD, I was told by Fedora that my system didn't use long instructions and to use a 32-bit distro.

I am planning on moving back to Fedora, since it's easier to use as a server, but I want a complete Linux network for once!

Am I right in this indo that I've found about the Sempron being 64 bit??  Or is the DVD having oddities...?

Thanks for your help!

-Jason