VST's won't play since PRO install...

I bought Cubase Elements a couple months ago. It’s been working great. During the holidays I had some extra time so i wanted to see what PRO was like. So I’m half through a 30 day demo now. My problem is that when I go back to Elements, my VST’s won’t play from my keyboard. The MIDI in Activity indicator in the lower right corner of the transport bar responds to all of the keys I press on my keyboard. So why the heck is the signal not getting to the VST’s???

I think I’ve figured it out, but I don’t understand it. For some reason PRO took exclusive midi out of channel 1 from my keyboard. While in cubase elements I switched my keyboard out to channel 2 and it works now. weird.