I know this one. I connected my V4 and V4.5 last night. For your V4.5 you choose Version 4 and V4.5 and on the V4 you choose Version 4. Then choose whether you want to do game, present, or visit and they will connect!!
Choose V4.5 and V4. And then choose either present your tama goes to a differant screen or the other tama comes to yours to give each other gifts. choose game and your tama will play a random game with the other tama
choose visit and your tama will go to another tama or vise versa and they will do little amimations together!