MIDI Problem (I'm full of problems aren't I?)

[DrumRookie]

Ok, so I have a Tascam US122L interface/soundcard that I got, and I have some questions with the MIDI on it.

Just today I got a MIDI to MIDI cable (not the cheap USB to MIDI one, I returned it because it was faulty). And I'm using GarageBand 1.1.2.
I plugged the MIDI IN end of the cable into IN end of the interface, and the IN end of the cable into the OUT end of the Yamaha PSR E203 level 1 MIDI keyboard.

At first it showed up on the little sound level when I pressed a key, but after I recorded a bit, stopped the recording, and went into some voices and settings and clicked safari to check email, I came back and it nothing showed up when I pressed the keys. I restarted the computer and achieved the same results as above. And now I'm stuck, not knowing what to do.
I may soon get an electric drum kit (thats why I think this qualifies as being fit for going into the drum recording section, because the same will apply for the drum kit because they have the same principals. And it seems inevitable that this will happen again.)

Let me know if you have any thoughts or help on this, I feel like I checked everything. The Audio/Midi Setup Utility doesn't tell me much either.
I'm using a Mac PowerBook G4 running 10.4.11.

[Scottie_Guns]

Should be:

Instrument - Yamaha (MIDI OUT) goes into

Interface - Tascam US122L (MIDI IN) then

Interface - Tascam US122L (MIDI OUT) connection goes into

Computer (via USB?)

Is that doable with your setup?

[rmandelbaum]

read up on MIDI, my guess is you did not assgin the MIDI input to any sounds.