I recently got Fedora Core 5 and have been bothered by many incompatibilities with AMD64. Will the i386 version work?

It should. Maybe you should compile the kernel yourself on your machine.

Yeah, AMD64 will happily be an i386 processor. That's its default mode.

Okay, now I'm trying Ubuntu, but the computer freezes and the login screen gets scratchy when I login. I had the same problem with Fedora Core 5, but it defaulted to text mode since I used text mode just to install it. How can I startup in text mode with Ubuntu to install the NVIDIA drivers?

When booting, it will ask you if you want to press ESC or something like that. Once you have done that, choose to boot into recovery console.

Thanks. I managed to dp that and get everythign working. SO far, Ubuntu looks a lot cleaner than Fedora Core.

If you're installing a standard 32bit x86 package on AMD64, try getting the K7 kernel instead of the default i386 one. That's teh AMD Athlon XP kernel, much closer to what you have than the stock i386 one and still fully 32bit. It's what I use on Ubuntu 32bit as well.

The simple answer to this question is yes- it should work. However, if you're running something in i386 mode, you will not get 64-bit functionality. This, however, will not harm your performance (unless you're perhaps coming from Windows 64-bit Edition).