[ubuntu] 10.04 install help?

Used to use Ubuntu way back in Dapper, but haven't since then... I've been trying to dual-boot Ubuntu [Lucid] since yesterday, on a freshly wiped hard drive. I installed Windows 7 first, made sure to leave a good chunk of HDD space for Ubuntu.

Anyway, I've tried both the x64 and x86 ISOs, and they both give the same issue. During boot, I get an 'Installation Failed' message, telling me it's going into Live mode where I can diagnose or try again. If I try to install from Live mode, I can get to the keyboard/locale setup, and then the installation just hangs. I can close the program and still use Live mode, but nothing else happens. I left it for several hours and it still was stuck at that step.

Also tried booting from USB [I didn't actually know my BIOS supported this, but I found the option after a good hard look] and all I get is a message 'Boot error.' and I have to reboot the computer.

Specs:
AMD Athlon64 3400+
3GB RAM
200GB HDD + 320 External
ATI HD Radeon 4670

Any help would be greatly appreciated!

also crossposted to gurnal

Jam it back in, in the dark.

I actually tricked it into installing--I heard other people had trouble getting it to recognize USB keyboard/mouse during the install, so I just unplugged it for a couple seconds while it did the hardware scan. It works now.

I've got a different problem now though, but I'm thinking it could just be the video drivers. The OS just runs really slowly, to the point where I can type a sentence and a bunch of letters get skipped over. I'm going to try the proprietary drivers next boot and see what happens.

There's nowhere I can't reach.