I am a long term logic user moving to logic pro.
Much of my work is still in Logic 4. I use a combination of Audio and midi.

When I open a logic 4.8.1 song in logic pro 7.1.1, I experience crazy midi behaviour.

For example, I record a part on the EP88 electric piano.
When i listen to what i have recorded, it does not make any sound at all. Then, after double clicking on the "reorganise memory" function on the transport window, it will sound. This seems to be the only solution.

If I then attempt to edit what I have recorded, logic plays the part in some random pitch - forcing me to reorganise memory each time I do any editing in the matrix editor! Progress is painfully slow - help!

My system is :

LogicPro 7.1.1
OSX10.4.6
Dual G4 1.25mhz with 2gb ram
MOTU 828mk2 with latest drivers

Are you moving from Logic 4.8 in Mac OS9 to Logic 7 in OSX?

If so then its probably an issue with audio drivers and you may need to go into the audio enviroment in Logic 7 to choose Core Audio as the audio device for each audio track / audio instrument track.

Not sure about the re-organising memory thing, never seen that option.

I'd set up a blank page in the new Logic matching the old document track by track and by tempo(s), Then just copy all info from the old page to the new one.

Did you attempy to just copy the Instrument Prefs and grouped your MIDI tracks?

Make a AAF/OMF?

It doesn't matter what audio drivers you had before. When I changed a long time ago, i'd simply drag the thumbnail (session) onto Logic Pro 7 and het presto it opened with no changes. If the MIDI goes haywire, why not check in MIDI prefs for any settings that might of changed.

Hope you work it out!