I'm glad you got a resolution that makes you happy, but I would advise anyone else out there that is thinking of getting an all in one keyboard with MIDI out to make sure it has a standard MIDI out port on it. Radio Shack makes lots of cheapie boards with MIDI ports on them. Built in speakers, light up keys in some cases and lots of built in sounds for little cash. Nothing that I myself would be happy with, but if you're only interested in something that satisfies the "I want it to make sounds on its own, plug into the MIDI adapter and not cost a lot of cash" than the Radio Shack stuff is the most cost effective solution going.
If you want to take a step up from there, get yourself a Yamaha "personal" keyboard. For just over $100 you'll be entering the "prosumer" level of keyboards. The sound engine will blow away the Radio Shack stuff, plus you'll get more polyphony (how many keys you can hit at the same time without some of them not playing notes at all) and more advanced features like reverb.
Hope this helps you.
At this point, make sure the correct device was selected as the input device by pressing some keys on your synthesizer. You should see some Note On/Off events and so on in the input monitor window. If not, try going back into Options>MIDI Devices and trying something different (ie. if you selected "USB Audio Device" for the input and "USB Audio Device (2)" for the output, you might need to swap the two so "USB Audio Device" is the output and "USB Audio Device (2)" is the input).
Lastly, open the Options menu and select "Data Mapping". Our goal here is an entry with wildcards (asterisks) in every column. If there isn't one, click Insert and ensure the top row of fields list the default of:
any any -1 -1 -1 -1
and the bottom row of fields list the default of:
Match input Match input -1 -1 -1 -1
and click OK, and OK again. Now run a MIDI cable from your USB->MIDI adapter's MIDI OUT port to the MIDI Pro Adapter, and ensure the adapter is connected to your game console with the instrument switch set to the "K" position. If all goes well, you should be able to use your synthesizer in Rock Band 3.
However, as far as I can tell (I've never seen one of these in person so can't verify) there's no pitch wheel on the LK45, so he won't be able to whammy sustained notes for extra overdrive (points). It won't affect whether or not he can play the songs, but it will limit his maximum score.
PS3 Expert Vocalist
Want to hear me singing? Check out my YouTube channel, user IcemageJT