melodyne essential - compatible with Reaper ??

have new mac - fast processor, plenty of mem, huge H D - shouldn't be a prob here.

problem is whenever i try to transfer the signal into essential. i click the
"transfer" button in essential but whenever i click the start button in reaper to begin playback, the transfer light goes out and no signal is transferred to essential. I've gotten around it this way: back up the playback track far enough so that i can begin it playing and then then click the transfer button in essential just before it gets to the point where i want data transfer to take place. but there's still a prob - it will transfer data for a short time ( 2 or 3 or 5 seconds) and the transfer button goes out ( light not lit) and the data stops transferring. with my mouse over the transfer button, i can click the transfer button and it will start transferring data again.
I JUST DON'T BELEIVE THIS PROG IS SUPP TO WORK LIKE THIS ! ! could this be because reaper does not support melodyne as a VST plugin ?

what about garrage band ? would essential work in there. if it does, i could always export the vox track to GB, use essential to pitch correct then import it back to reaper.

as always - any help app

5string