iMac (2.4 GHz duo core) analog audio in as input (?)

[ij384]

I recently upgraded from a G4 iMac to the new titanium core duo iMac, and, upon installing Logic onto my new machine, found that I was unable to use the analog audio in as the input for my audio tracks. This is distressing to me as this is the only input I've ever used (I have a very bare-bones setup), and now when I click on the track input I am greeted with a "no input" box, whereas before I had the options not only of line in buyt also dv audio in. Is there any way I can rectify this? No additional setup was needed for these options on my G4, so I'm at a loss as to where to even begin.

 

By the way, I'm still using Logic Pro 6, and for all I know this makes all the difference in the world. I was just wondering if anyone knew how this problem could be solved before I jump for a (admittedly overdue) upgrade.