I just connected the M-audio usb to my macbook, installed the drivers, restarted, launched Garageband, and am not having any luck getting sound input from my microphone to Garageband. I did set the preferences for Garageband to use the M-audio for audio in and out. A little help here? thanks!

Make sure your preferences settings in the MBP are set to use that input. USB recording is not the best way to do things. I'd look online and buy an inexpensive interface, like a Lexicon or Presonus etc, then the interface will connect via USB, but your mic will go into a genuine XLR input on the interface. You'll also benefit from much more gain and level control.

The guide fro properly connecting your microphone is here
GarageBand 11 Connect microphone

The problem is with OSX and its usb bus and not your settings or your usb device.

The solution to your problem is to use a firewire soundcard. That way it will use the firewire bus and all should be fine.

I restart with the CI1 plugged in) but I can't 'get it' in Garageband. I've tried the Garageband preferences, and system Audio section, but there's no device to select there - only internal mic.
Be sure to get the latest update from Steinberg.net
And in Garageband you'll find your unit in preferences - input

Your best bet is to get a "midi to usb" cable. is use the M Audio Uno and have had no problems, then it will record as midi, so you can edit the hits later if needed.

use the audio output to send the keyboards internal patch sounds, or use a usb midi adapter to use the keyboard to trigger the garageband midi sounds, if the keyboard has a midi output, that is. the usb output requires software drivers to use, and IS NOT mac compatible. You may have to select a midi source in garage band preferences or settings if you are using midi.

Just did it today. Hooked up CTK-720 to Imac with Snow Leopard (10.2.6) using GarageBand.
Steps: 1) Go to : http://code.google.com/p/casiousbmididriver/ 2) Download the CasioUSBMIDIDriver.plugin (see the two choices on the right side of screen) 3) Place the CasioUSBMIDIDriver.Plugin file into the MIDI Driver subfolder: Macintosh HD => Library => Audio => MIDI Drivers 4) Restart 5) Plug in USB cable, open GarageBand, turn on Casio 6) In GraarageBand Open New Project, Start by using Piano, Select Keyboard (command K) in the Window menu 7) You should see the keyboard being played on the screen.
PS: Thank you Francois Ferland.

To get sound in both channels in Garageband for a podcast using the G-Track Microphone:    select a voice track to record into    make sure the Track Info window is open (blue i button in lower right region of screen)    at the bottom of the Track Info window you will find Input Source:    Change the default setting of Stereo to Mono 1 (USB Audio CODEC)
This assumes you have gone to Garageband preferences and changed the Audio/Midi settings for audio input to USB Audio CODEC which appears when you plug in the G-Track Mike

i need sound drivers

I had the same problem. When I installed the Edirol software it prompted to 'reboot' and when it restarted all the lights on the Edirol came on.
Why don't you try it like that.
Hook up the Edirol Install the software Reboot
Best of luck Victoria

Use a 'Y' splitter. Usually from balanced to unbalanced. Also try looking at your device's control panel and see if you can change the channel options from mono to stereo. Beta drivers are for testing purposes, so try the signed driver also.