Presumably one of the keyboards is the M-AUDIO…?
What’s the other one?
You need to have each of the keyboards on different MIDI channels really. There isn’t an easy way if both keyboards decide they want to be on channel one. . .
But if you want to remap a board from one channel to another you can do the following …
Which MIDI channel does it transmit on, when it starts up? Because we can use MIDI mapping in the webconf . . .
The MIDI mapping takes place at the bottom of the MIDI page in webconf, but do make sure you turn on advanced to see it !!!
Press the Plus symbol under Midi filter rules:
Select the MAP Rule . . .
and you can change a channel to another channel …
Problems come with the second keyboard if it ALSO transmits on the same channel because there’s not really a way to separate sources by USB Device.
So your first concern is to work out a way of making sure the two keyboards occur on different MIDI ports, and that s probably down to some almost always Windows based set up programme supplied and downloadable with the keyboard itself.
Sorry if this all seems a bit long winded but it does get a write up of MIDI mapping … 
and don’t think we wont want a 
…