I run Logic Platinum in OS X on a G4 800. My MIDI I/O is a MOTU MicroExpress.

I start Logic and both of my MIDI inputs work fine (a keyboard and a drum trigger). MIDI data is recorded as usual. But I'll pause for a while to program a patch or read a manual, and the next time I hit record no MIDI data is recorded. The MIDI input monitor shows that nothing is going in, but the data already there still plays my synths.

If I quit and restart Logic, all works again.

Any help would be appreciated...

-Smplfly

I had this exact same problem earlier this week. My Midi I/O is an Emagic MT4. The Logic InfoWeb recommended trashing the Audio Midi Setup preferences (in Library/Preferences, called something like apple.audio.midi - check this before deleting!!) and logging out. Not that it made any difference. Quitting and restarting or occasionally restarting my entire Mac fixed it.

However, this is what Emagic support e-mailed me later:

I would like you to try using MIDI on a default logic song.

While in Logic hold down alt and at the same time go to your file menu and select new.

A default song should open.

Now play on you keyboard.

If you cannot see any Midi in on the transport bar you have a problem with preferences if you do have midi in you have a problem with one of yoyr existing songs.

BTW, all typos are theirs ;-)

As my set-up is working again without doing this, I haven't had to try it so I can't vouch for it either way.

I'm having the same problem..

Using logic audio 6 in osX.3 on an iMac G4, and reason 2.5, with a midiman keystation 49 and USB quattro device. The midi works on booting up either logic or reason, then the signal appears to be lost after 2-3 minutes. Logic then tells me the number of midi ins & outs has changed to 0 (3 on startup).

Reinstalled up-to-date drivers, everything... no good.

Had an idea... borrowed a friends cubase disks and installed - cubase runs fine, but midi disappears exactly as it had before in logic and reason.

Gotta be a panther/jaguar or midiman driver issue, surely??

Fix it someone!!!

Got another one for yall... When your midi fails, try unplugging the USB cable, then plug it back in. This usually worked in the good ol days, when I was using M-Audio suff... now I've gone to Mark of the Unicorn Fastlane, and all is well in Panther.