*NEW* SGS2 MIUI V2.3.23 Call Recording WORKS LIKE CHARM!

hmmm odd you sure its not there ?

Settings > display then scroll down and see screen animation on and screen animation off
affff your on v4,0 miui. Then it should be enabled by default if not then possible its not enabled just yet - this is a new fresh build for sgs2 so give it time to mature.