You do not have to push it. But I did a lot of times using photoshop and video rendering without problem.
I had these lines at the past, but they did not reappear since September.
My system is Vanilla plus the Extra.kext of bkribs from the first thread with these kexts inside
AHCIPortInjector.kext
AppleACPIBatteryManager.kext
AppleHDADisabler.kext
ATAPortInjector.kext
FakeSMC.kext
JMicron36xATA.kext
JMicron36xSATA.kext
JMicronATAInjector.kext
PXHCD.kext
VoodooBattery.kext
VoodooHDA.kext
I am having the model with HD3000 only, F,09, 10.7.1 and the second memory is the cheapest I found at ebay for 18~ Euro.
I post all this info a lot of times and if you want the link for the Ram I can search later for you.
I do not know if I have the magic hardware-software combination, but is working perfect (at least up to now).