Here's the hardware first:

---First Shipment---
Monitor: Viewsonic VA721
Motherboard: ASUS A8R-MVP Socket 939 ATI Radeon XPRESS 200 CrossFire
CPU: AMD Dual Core Opteron 170
CPU Fan: ZALMAN CNPS9500
Hard Drive: MAXTOR 250 GB HD 7200 RPM 16 MB Buffer Ultra IDE 150
Optical Disc Drive: BenQ 16X DVD±R DVD Burner Model DW1650 BG
RAM: G.SKILL 2GB (2 x 1GB) 184-Pin DDR SDRAM DDR 400 (PC 3200) Unbuffered
Graphics Card: SAPPHIRE Radeon X1600PRO 512MB GDDR2 PCI Express x16
Power Supply: ENERMAX Liberty ELT500AWT ATX12V 500W
Mouse: LOGITECH MX700 USB + PS/2 Wireless
Keyboard: DCT FACTORY OG-203B Black USB + PS/2 Wired Slim

---Second Shipment---
Floppy Drive: MITSUMI Beige 1.44MB 3.5" Internal
Sound Card: Creative SOUND BLASTER X-Fi Platinum 7.1 Channels PCI Interface

----

I finally finished saving up for and building my new comptuer about two months ago. Sure, I'd be adding some parts (like the soundcard) in a second shipment a few weeks later, but I had what I need to get up and running!

I could run all the unix distros I wanted, from the easier ones (Fedora Core 4 and 5, Slax, Knoppix, Ubuntu, Linspire, etc.) to the less mainstream (BackTrack, PHLAK, FreeBSD*, OpenBSD*, etc.). Like most unix users, I had Windows installed and would either dual-boot or run live CDs.

*Didn't get to a GUI for these guys, but that's because I didn't know what the heck I was doing then.

At first, the only funny thing was that whenever a distro wanted to display a picture at the boot menu, it'd be messed up (like they were inverted, so the Slax clover showed up in a weird, bright pink). But that was no biggy since after the distro actually loaded, everything displayed normally. It'd be nice to have the boot menus not look funky, but whatever.

However, for a while now, it hasn't been working so well at all for my distros. They'll get me to the boot menu just like it used to (still looking funky if that means anything), let me pick whatever options and stuff I want, and will attempt to proceed. But then after it runs through loading the hotplug module and all that, bam. Won't work. Some of them just give me the user input bash, others make the monitor say "Out of Range" and so forth.

Funny thing is, I can get Slax and DBAN (and the Windows XP Pro installation CD) to work! I'm still going through all my distros to see if any others work. PC-BSD and Slackware will let me install to the hard drive fine, and then will get to the boot menu too after the reboot, but then they act like the others and don't work. It's important for me to note that they don't seem to go unresponsive. I can watch it claim to load all the stuff when I turn verbose on, but then they just don't work.

I'm perplexed because all these distros were working for me, and then all of a sudden, nope! Not going to happen. Is it possible that something in the second shipment might've caused this? Probably worth investigating. Before I go and take out the soundcard and the floppy drive, is there a cheat code or something I can enter for it to just ignore them? Well, I guess that'd depend on which distro, huh. Here are the other distros I've tried recently in list form along with their current status:

Slax: Works
Slackware: Installs fine, then won't work
PC-BSD: Installs fine, then won't work
Elive: Won't work
BackTrack: Won't work (funny, since it's Slax based)
PHLAK: Won't work
Grafpup: Won't work
Kororaa XGL Live CD: Won't work
Dynebolic: Won't work
Musix: Won't work
Frenzy: Won't work

Any suggesstions?

Anybody???

Your question is extremely vague.

How about posting up some of the error messages you get?

Saying stuff like "won't work" doesn't help much.

I've been as precise as possible. In other words, I would say what error message it gives me, but it doesn't give me any message. When it's done going through the verbose boot process, instead of "startx" taking me in, either nothing happens at all or the screen goes black.

Is the problem still vague? Yes, hence my own frustration. I figured the best I could do would be to post up the hardware and the distros tested, but beyond that, I don't see any information I can provide (that is, no error message).

Perhaps you could tell me to input some strings and I'll tell you what it responds with?

Just a longshot..

What happens if you change "dual slot configuration" from "auto" to "single slot" in the bios, it should be located somewhere under advanced in the bios options.

( remember to set it back to auto if you buy a second videocard )

Didn't make a difference. Good idea though. Any others?

If you hold Shift while pressing page up, you'll be able to scroll back up through the "verbose boot process" and see if there is anything strange.

Also, the contents of these files under /var/log:

syslog
Xorg.X.log
messages
dmesg

should provide some idea of what's going on.

Please post any apparent error messages and we'll try to help you.