AAC audio is not being recognized immediately after itunes v9 install. Uninstall does not fix issue. Coming up 'stream attributes could not be determined".
This is the new Quicktime update. As a workaround re-installing the previous version enables Vegas to see the audio. But what's the answer to the new update?
Rolling back to iTunes version 8.2 and QuickTime version 7.6.2 definitely solved the problem. Left feedback with Sony, Apple, as well as with my neighborhood Apple store.
Good luck getting anything answered by Apple / Quicktime / iTunes.
You may have better luck getting the issues addressed by Sony, although every version of QT is broken to some degree since 7.4 . . .
Just today I came to the forum to look for answers for the very same "problem". I am working on a Vegas project finishing the video edit and have started to work on the soundtrack. I had a DVD from a friend with a whole bunch of AAC files and I could not get the "capture audio from CD" to recognize the files on the DVD because of course it wasn't a CD. So then I tried to "import media" and at first it would show the files and I could see the files but could not bring them into Vegas. I got the message that I needed a program to associate them with so I downloaded Quicken which improved things slightly because I could now bring the files into the project folder but there was no data. What I did was first, unistall Quicken from my Vegas working computer because I never wanted it or iTunes on my audio / video working computer, and then opened iTunes on my Desktop. Then I put the DVD into the computer and though I didn't get the prompt to rip the disc I was able to just copy them into a "playlist" and from there burn the tracks (all 150 of them) to four audio CDs which of course very easily allowed me to capture the audio from the CD into my Vegas project. I confess that I tried a Mac and Final Cut before buying my Sonica LiveTracker II and Vegas and though part of me wanted to be an Apple person, I pretty much hate everything Mac. Hell, I don't even eat apples.