I’m attempting on installing Haiku on my custom-buit PC with has an Asus M3A78-CM motherboard. The motherboard specs are an onboard ATI RV610 GPU, HD 8-channel audio codec, and an AMD Athlon 64 X2 CPU. The problem I’m having is that on boot up, the OS installer freezes up on the third icon. Does anyone know what might be causing the installation to freeze on boot up?
yes, your hardware. 
There are two main causes, either video or disk. Go into safe mode and try options there:
http://www.haiku-os.org/docs/userguide/en/bootloader.html
disable DMA, if sata try ahci & legacy modes (change it in your BIOS), try fail-safe video mode + 1024x768x32 resolution.
if those don’t fix it, enable console debug in safe mode & try to see what is causing it to hang. Also, if installing Alpha, you might want to test with nightly image & file bug report.
I’m getting something from the debug console: PCI: [Athlon64/Opteron] host bridge capabilities: (not supported)
Should look to see if you get any error message in debug console too.
try out nightly image & see if that works for you. Did you check your sata settings in your BIOS? Did you try to change to AHCI & Legacy modes to see if that worked ( one or both of these should ).
Otherwise you’ll have to file a bug report with photo of console debug output + hardware configuration ( in linux, lspci -nn ).