RegWriteDWord( "HKLM", "System\CurrentControlSet\Control\Power\Timeou ts", "BattSuspendTimeout", 300 )
I copied and pasted the code from the script that runs from my sd card. The only reason it starts on first boot is because I cooked Mortscript and the "Loader" script for my customizations into my ROM. More information can be found on the ROM page in my signature.
Edit: Looks like there are spaces shown that should not be in the code. You may be better off copying and pasting directly from the script file here:
ftp://up.ppcgeeks.com/Vogue/Users/Bo...SE_2/test.mscr