There is no 1.2 released..
its 1.1 that is released.
ohh and for Baby Vegeta.
You cant play with 1.0 against 1.2
cause..
1.2 will have advanced melee. maybee a new character (not sure/Cant remember) and some other things.
and 1.0 is just old now.
go download the updater from 1.0->1.1