Update: The problem was resolved by installing the Perian plugin. This answer was provided by a commenter. I am forever in her debt.
Now, I heard back from Pure Digital support just this morning. This means they violated their 4 hour turnaround time that they promised. Sad. Even more troubling is there response. In my note to them, listed below, I mentioned that I run Leopard and have the latest version of quicktime, right? Here’s a screenshot to prove it..

So, what do you think there response was? Here it is…
Dear Chris,
Thank you for contacting us.
We have recently become aware of an audio compatibility issue revolving around Flip Video and the QuickTime 7.4.5 update running on the Mac OS X 10.4 Tiger operating system.
This issue should not affect customers running the Mac OS X 10.5 Leopard operating system.
Apple has released an updated version of QuickTime which resolves this issue. Please upgrade to QuickTime 7.5 to regain your audio.
We apologize for any inconvenience this may have caused. Please do not hesitate to contact us for further assistance.
Thank you,
Flip Video Support
Obviously they did not read my original message, and that’s incredibly irritating. Shame on Pure Digital!
Original Post begins after this line…
So I just bought a Flip Mino camera. The trouble I am having is that when I import the video I get no sound. I emailed their tech support with this message.
Hello!
I purchased a Flip Mino yesterday and when I import videos onto my Mac, I get no sound. I hear sound if I play the video in the Flip for Mac application, but when I view the AVI in Quicktime, there is no sound. I tried importing into iMovie and there is still no sound. I tried playing the AVI in VLC Player and no sound either.
I saw the Q&A on this but I am running the very latest version of OS X Leopard (10.5.4) and have all the updates. I recently updated to iTunes 8 and Quicktime’s latest version, so it does not fit the mold of the question previously answered. Please don’t just copy and paste that Q&A to me.
Thanks for your help..
Chris
I am posting it here in the hopes that one of you has seen or heard of this and might offer a suggestion? I know this was an issue with Tiger at one point, but that doesn’t fit me. I tried the usual searches for answers and nothing. Any thoughts?
I’ll update this when they get back to me, supposedly within four hours. I emailed this around 10:00am EST on Saturday, Sept 13, 2008. Let’s see if they stand up to their promise…