No midi control in GB '08 with keyboard via Alesis io2, & no output via io2

The lengthy title sums up the two key issues I'm having.

I'm using an Alesis io2 USB interface, to run guitars and midi controller keyboards (goldstar MK49 & Terratec Midimaster Pro) into GB '08.

There're no problems getting the guitar into GB and my Guitar Rig 3 plugin, and no noticeable latency on monitoring via the system output (active speakers from headphone output). Until three days, ago I was also using the keyboards to successfully control software instruments in GB.

In detail, the issues I'm experiencing are:

*1) MIDI Keyboard*
After attempting to create a new aggregated audio/midi device in the Audio Midi Setup utility, I can no longer get the keyboards to work. I get intermittent notes at random and also when using the keyboard data sliders, but mostly silence. Previously I had no problems with velocity sensitivity, note, modulation, pitch or track level control. Now, I'm getting nothing other than random notes.

It appears that GB, my MacBook or both are now unable to make any sense of the midi data they're receiving. I've deleted the aggregated device via the same utility but still no control. I've not yet found a 'MIDI reset' option in system prefs or the audio/midi utility. Any suggestions how I get my bits of gear talking to each other again?

*2) Audio output via Alesis io2*
SInce getting this USB interface I have been unable to route any audio back out of my MacBook through it; either to headphones from the built-in headphone jack, or monitors from the 'main L/R' connections. System prefs and the audio/midi utility both see the io2 as a device with 2x ins and 2x outs, but both tell me the device has no output controls.

Creating a new aggregate device didn't work, so any ideas how to resolve this one? Also, could creating this new aggregate device have contributed to my first issue?



Any advice would be gratefully received.

Thanks in advance.