You have to change the code in some places.
If you feel like waiting 2 days, i think i should be able to get Memberlist 6.3.9 out this Sunday.
6.3.9 will be a basic conversion from the ubb6 version of the mod to 6.1. 6.4.0 will be a bigger Memberlist release I am planning that has a lovely bulk of new things.
Keep your eye's peeled on the Beta Mod's forum.