I realise that this is an old post but I'm having exactly the same issue as the OP.
My build is the original Hackintosh per my sig barring the graphics card - which is now this:
1023MB NVIDIA GeForce GTS 450 (ASUStek Computer Inc)
Here's the back story:
About two weeks I started re-installing Snow Leopard on this rig after a hiatus of a few years from OSX.
I installed Snow Leopard using the recommended iBoot and Multibeast, no problem.
At some point I'd messed around adding a few things and decided to start again with a clean system prior to migrating to Yosemite... and this is where the wheels feel off.
I couldn't reboot from the iBoot 3.3.0 disk. It will proceed to mount the image then hang without reaching the GUI.
Note 1 After setting the BIOS (rev. F8) for the initial install which worked, nothing had been changed.
Note 2 I only had a mouse & keyboard plugged in, no other external USB/Firewire stuff, no additional SATA HDD (Windows 8.1 - which works quite well thanks)
Note 3 I decided to give it a miss and went to install Snow Leopard on the Asus K53 laptop and whilst that's another story in its own right, needless to say, the boot disk worked so the disk is fine
So I come back to the Hackintosh desktop, try iBoot again - the same CD - still no boot.
Note 4 I burn a new copy of iBoot - in fact I burn about another three copies of iBoot, none of which work in the desktop but it boots up fine in the laptop. I'd even redownloaded the ISO of 3.3.0 at this time and nothing changed.
Note 5 I suspect the SATA cable to the DVD burner. Change it out, no boot.
Note 6 I remove the drive so that the SATA cable is not routed past the unconnected power leads - should make a diff but I did it anyway - still no go.
Note 7 Bought a new DVD burner - another LG... maybe there's a pattern here... - only this model is the:
HL-DT-ST DVDRAM GH24NS90 . Same thing; no boot. In desperation, I even changed the port which the DVD was attached to no good, went into the Boot order in BIOS and selected the DVD by name rather than the generic CDROM entry - that didn't work either.
Note 8 Burnt some more CDs using the new burner. Still no boot.
Note 9 Cleared and setup BIOS settings again, reboot from new CD. No boot.
This is as frustrating as all hell. Nothing changed other than me deciding to start a reinstall from scratch.
The only thing I have left is to physically pull the graphics card and all SATA cables out and reseat them and bearing in mind that Windows is ticking along quite nicely without doing any of this.
It's almost as if at some point the LG drive in this combination has gone tits-up.
I've tried finding advice regarding booting iBoot from a USB stick and there's nothing. I tried using YUMI but of course St Murphy of Sod's Law decreed that I wouldn't find how to set that up either.
Which does beg the question, why, when Uniboot is USB stick-based, is iBoot still only providing instructions for booting from CD?
The question is not meant as a measure of disrespect for the fine work which has gone down here but it seems a bit weird that after all this time that anything bar Snow Leopard installs uses USB to boot from.
Edit 1
Ahhhh! Just remembered!
I'm not connected to the VGA port - I don't think I swapped from VGA to DVI at any point between installation attempts but it's the only other connection that's different from when I'd originally installed Snow Leopard years ago...
Edit 2 ... nope.. .that wasn't it either...