You'll want to make sure it's monitoring through the track if you want it to play back realtime. I forget how it works in Cubase 5 VST/32, but in SX (1 at least, haven't used the newer versions) there's the monitoryness button under the record enable button, and if you select that, then you can play through the track with effects and amp sim (if you have any amp sim plugins) and whatnot. Dunno if this is what you need, but if it helps, then all is right in the world.