Pro Tools Midi Playback

[taperocket]

Ok,
I've put this question off for some time for risk of sounding like an idiot but I can't seem to figure this out! I'm running Pro Tools 7.3.1 on OSX 10.3.9 on a dual G5 with 3 GB memory so I should be all good but I can't seem to get my instrument tracks to play back!

Here's what I do.
1. I set up a new stereo instrument track.
2. I insert either reason 3.5, analog factory (demo), or xpand in the insert section of the track. I have my midi keyboard set to use channel 1 as the global channel.
3. I press record and I record a synth sound which I can hear just fine at this point and I see the midi notes written out in my PT edit window.
5. I deselect record on the channel strip
6. I change the input to no input.


At this point I can't hear the midi notes playback at all, if I reselect channel one, or no input or output 1-2 the sound will kick in briefly and then go away. What am I doing wrong here? Please respond as I am at my wit's end with midi!
Todd

[taperocket]

c'mon, help me out so I can get back to making music!