OS9.2 iBook oddity with MIDIsport interface, iBook recognizes Midisport 2x2 but won't talk to it... Options

Hi folks:

I have used Performer 6.03 on iMac with good results for several years.  I recently started to transition to an iBook, and have run into trouble.

My studio consists of: Midisport 2x2 interface, Korg 05R/W sound module, Korg M1 controller, and Tascam Mixpad.  The hookups are pretty basic: 05R/W and M1 both go in and out of the interface (4 connections total).  Audio cables from 05R/W to mixpad (headphones), USB cable from interface to iBook port.

So far the following seem to work fine:
* OMS (latest version) - studio setup recognized Midisport and sound module;
* Performer - loads OMS studio happily;
* M1 - sends signals to interface (In-A light responds).

Here is what does not work:
* When a multi-track song is played in Performer, it fails to send a program change signal to the 05R/W, nor does it appear to be sending any type of signal for that matter: the In-B and Out-B (to which the 05R/W is connected) lights on the interface do not indicate any signal, nor does the MIDI light on the front of the 05R/W.

After checking product FAQs online, I spoke with the folks at Performer, who thought it was an interface issue.  The folks at Midiman feel it is a computer issue.  I agree... since the computer is the newcomer!

I downloaded the floppy enabler (as recommended by Opcode) and also discarded one of the superfluous driver files from the System folder (also recommended by Opcode) - no effect.

Throwing everything away and doing a clean start-over (Install OMS, reboot, install Midisport driver, reboot, shut down, connect USB, reboot, configure OMS studio - the procedure suggested by the Midiman team - again sans succès...

Any tips of leads on this matter would be extremely helpful!

Thanks,

Ric
Tennessee