A few things come to mind:
1- maybe you tried to insert it is an FX in the bin instead of a Synth but in the FX bin.
If not that then ..
2- After you set it up via Pluginmanager, make sure you exit pluginmanager and only after you've done the setup should insert Stutter Edit.
IOW - if you already had it inserted it won't work until it has the right parameters.
One way to check is to start a fresh project, go into pluginmanager and look under VST Intruments. Stutter Edit should up there and NOT under VST Effects.
If it does, try loading an audio track (wav or something), insert S E into it's FX bin as a synth.
Then create the MIDI track to trigger it as per my outline.
Does this work ? Let me know.
Oh - and do you actually SEE Stutter Edit in the list when you go to insert it in an FX bin?
I don't know if it's 64bit yet or not, so maybe that has something to do with it too.
I tried the demo and it worked for me in 32 bit. I decided not to buy it, so I can't really tell ya much more :(