I also had a troublesome Falcon RGH2 (5774) that was giving me some trouble. I tried the SMC configs posted..none in which worked. Actually that's a lie. When d**ko sent me the No_Freeze SMC, it booted like once or twice with no freezing. But after that..constant glitches but not completing the boot cycle. It also only booted 2 times out of 10 with Shielded Wire (Grounded) but the same symptoms as you Martin, freezing and stuttering during boot up and when trying to play a game.
My stress at this point had gone through the roof... Eventually instead of inserting other SMC configs into my NAND. I manually edited them with J-Runner.
My ANA Fuse was already at 03 and Power VCS Control was already at 8555. So I couldn't see the problem. So I started to edit them one at a time starting with the Power mode, which I bumped up to the good ol' 8480, reflashed my NAND with the wonderful NAND-X and when it booted...there was no freeze anymore. It was just a case of tweaking the CPU_RST now. Since I had no luck with the shielded cable. I went with the Slim CPU_RST (50cm) out of the Slim wires and installed that..routed over the DVD drive and Fan shroud. Of course I had to do a criss-cross type route for the CPU_RST to get decent boot times (5 seconds to 1 minute usually) unfortunately I only have the older image of the wiring route..which also worked quite well..
But yeah..other than that it worked fine.
For those wondering my CR3Lite settings were the following..
LK1 - Bridged
LK2 - Bridged
LK3+4 - Unbridged (of course)
S4 - 1 ON, the rest off
S2 - 1 ON, 5 ON and the rest off.
Hope that helps someone at least.
I would like to thank d**ko too. Couldn't have kept a clear mind without him.