I just purchased GR yesterday, and I am having a similar problem with it. I have either Channel 1 or Channel 2 for the audio choices. It probably should pick up the audio from the computer (Mac) "Line In" sound input so you can record. For some reason the software thinks there is either a channel 1 or 2 that the audio should come in on, but this is a Mac, not a PC? I too am able to record using WavePad... Line In is there to select and it works great, but I need software to transfer my 1,200 albums to digital. I don't want to babysit WavePad to break each track into a song, put them together as an album... yada yada... Can we get some support NCH?!?! (Or... how do I get a refund?)
