I recently reinstalled Cubase VST5.1r1 and Reason 2.5. I had a try at using rewire for midi control of Reason but went back to my previous method of using MidiYoke (the main reasons being that Cubase VST doesn't store the rewire midi channel info as part of the song and there is a limit to the number of rewire devices that can be listed within Cubase VST5). But for some strange reason, I now cannot stop Reason transmitting it's midi data to Cubase when I move the main controls of the Reason devices - for example - I have two nnxts setup in a rack - one set to recieve on MidiYoke1 Ch1 the other on MidiYoke1 Ch2. If I select a track set to MidiYoke1 Ch1 on Cubase but then move a control on the Reason device set to recieve on MidiYoke Ch2 it retransmits this data to the currely selected Cubase channel and, therefore, thru to MidiYoke1 Ch1 and thus moving that control on that device (basically "midi-thru"). This is no problem if you are altering a control on a Reason device which you have selected in Cubase at the same time, but can be a pain in the backside when you tweak a different Reason device and subsequently this midi data is sent from Reason to Cubase and thru to a different Reason device.
I never had this problem before and I feel really silly not being able to solve it - it's so stupid but I have checked everything that I can think of and can't prevent Reason sending midi data to Cubase. I know it must be something obvious and I will feel like a right prat when I find out, but I will be a happy prat