Tried the above solutions, but they did not work for me, but I did find a quick fix that did work .
I have a little different set up then above due my set up is for Mythtv.
The connections are as follows.
I narrowed it down that the PC would boot if a regular monitor was plugged into the PC FX5200 DVI, or if there was nothing plugged in to the PC. Looking at my logs there was never any boot log made when the PC was connected up normally as above, so the boot process must had been stopping at Grub. As report above I had no issue when running 8.04 but this used the old Grub, and 10.04 uses the new Grub. To fix the issue I did as follows.
PC FX5200 DVI -> DVI+SPIF to HDMI "monoprice unit" -> 4-WAY HDMI selector "monoprice unit" -> TV "Sony 52 inch"
Open a terminal and type in this command
Find the line below and remove the "#" save the file and close gedit
sudo gedit /etc/default/grub
Next update grub by doing this command in the terminal
Reboot the machine.