If you run Logic and want to be able to overcome the GPO pitch bend bug (where whole step pitch bends go sharp in either direction if your pitch wheel is fully + or -), here's a solution:

1. Create a new instrument (or multi) in the Environment, name it, and click it's 'icon' checkbox

2. Create two new transformers. We'll call them "A" and "B".

3. Cable objects as follows:

New Instrument---->A----->B----->Audio instrument (using GPO plug)

4. Settings for Transformer A
(controls range of pitchbend down)

--------------------Conditions-----------------------
Status = PitchBend
Channel = ALL
-1- = ALL
-2- = Inside, top value = 0, bottom value = 6

--------------------Operations-----------------------
Status = Fix/PitchBend
Channel = THRU
-1- = THRU
-2- = Fix, value = 6


5. Settings for Transformer B
(controls range of pitchbend up)

--------------------Conditions-----------------------
Status = PitchBend
Channel = ALL
-1- = ALL
-2- = Inside, top value = 122, bottom value = 127

--------------------Operations-----------------------
Status = Fix/PitchBend
Channel = THRU
-1- = THRU
-2- = Fix, value = 122


6. Finally, assign your track to this new instrument instead of whatever GPO instrument you'd normally use.

NOTE: this will only work properly for those GPO instruments that sport the pitchbend bug such as the solo strings (range of bend = whole step). Solo Clarinet, for example, does not seem to suffer from this bug (and its range is only a 1/2 step).

With this workaround you are still recording the full throw of pitchbend data. The data is truncated by the transformers as it approaches the instrument plug. This means that if ever the bug is fixed in an update onme of these days that you can still play back your older tracks and hear the correct amount of pitchbend; all you'd have to do in this case is reassign your tracks to directly connect to the original GPO instrument as you would normally do.

Hope this proves useful to someone other than just me.