ASh, the Rom is same as you have perhaps... i.e. mik_os CyanogenMod 7.1-RC1 (Android 2.3.5) 6.5.7.
THe screenshot was with moderate use of Wifi plus GPRS with twitter on demand plus few mins of AQngry birds and Cut the rope. And few phone calls.
Usually mine does last for ~2 days unless my daughter gets it for few hours.
Also keep in mind, I got juice defender free running along .. may be that makes some difference.