Hi, jh:
You don't specify what your playback device is.
If you lose sound when you disable the Microsoft GM device, it seems like you're going through that. Disabling it really only affects use of ASIO drivers for soft-synth playback, such as Sherry Crann's favourite SynthFont.
Why do you need LoopBe? Are you using VSTHost or something similar to play back through soft-synths?
If you're playing back through the same keyboard you're recording from, then you can test it by going to MIDI DEVICE QUICK SETUP (Setup menu), selecting the device your keyboard is connected to and clicking on TEST. If you hear sound, then your keyboard is receiving. Play a few notes on your keyboard and you should see the DETECT MIDI RECORDING DEVICE respond. At this point, we know your keyboard is set up properly.
Now, turn "LOCAL" off on your keyboard (if possible) in its MIDI setup, which means that it will only sound what it receives at its MIDI In, while still sending MIDI out. Run Composer, load a random file, click on the Staff Setup (Speaker icon) to the left of any staff (making sure that staff is set to play back to your keyboard's MIDI device) and try playing a few notes. You should hear sound from your keyboard with no discernable delay as the MIDI goes from your keyboard to Composer and directly back to your keyobard. Other than an old-fashioned IRQ problem (which shouldn't be possible anymore), I really can't see how there would be any delay there.
If you're using soft-synths in a host program and you have not installed ASIO drivers (such as the freeware ASIO4ALL) for that host program, then you're pretty lucky to have only 1/8th note delay! If you do have an ASIO driver installed, you can adjust the latency of the playback in the setup for the driver. With some fooling around, you should be able to get to little or no discernable delay. If you need it, check out ASIO4ALL (
www.asio4all.com)
Either way, latency shouldn't really be a problem that is directly related to Midinotate Composer, as it, in itself, doesn't produce the sound, merely pass MIDI information to a sound-making device.
Good luck.
David