Unable to hear guitar using audio interface (UA25EX) with Garageband '11

Hi,

I cannot hear my electric guitar when playing in Garageband. I can hear all other sound from the computer and other tracks in Garageband I have successfully used the exact same equipment previously however since upgrading to iLife '11 I have not been able to get it to work.

I'm running the guitar through UA25EX into Garageband '11 on MBP running OS X 10.6.7. I have tested each piece of equipment separately and everything is working as expected.

I am ensuring the input and output source is correctly selected within Garageband Preferences and System Preferences/Sound. The MBP can "see" the UA25EX without any issue. I have uninstalled and reinstalled the driver for the audio interface (taken from CD-ROM). When I plug headphones into the audio interface I can hear my guitar. This leads me to think there is an issue getting the guitar sound from UA25EX to MBP (although I know the USB cable is ok as the MBP recognises the device when I plug it in).

I am choosing the Real Instrument track when beginning a new project and following the onscreen instructions to allow me to hear my instrument through the computer as I play and record.

Monitoring in ON, volumes are all high. I cannot manually adjust the Recording Level in the Track Info Pane as it is dimmed but I understand I simply control the volume with the guitar and audio interface, of which, all are high.

I have also followed the manufacturer instructions for the UA25EX to set that up correctly. I'm almost sure it is right, however, I don't know if the sample rate being set to 96P is correct? I have chosen that as when I select the input source in Garageband it reads "Mono 2 (UA-25EX 96kHz PLAY)"

I've restarted my computer several times to see if the on/off method works.

I really hope I am missing something incredibly simple here and it's not a major issue.

Please if anyone can offer any assistance I would be ever grateful.

Thanks.