The Mac version can certainly work with DV-AVIs -- video from miniDV camcorders captured over FireWire.
What type of camcorder did your video come from?
No camcorder, I work with 3D animated renders. I had a .wmv render from an older project that PrEl 9 refused even to ungray in Finder when I tried to import it, so I converted it to .avi using Any Video Converter. Finder then allowed me to select it, but PrEl wouldn't import it into the project because of a "missing codec."
I noticed the Mac version of PrEl 9 won't even save video in anything but .mpg or .mov (whereas v8 for Windows used .avi as a staple), so it's natural to wonder whether they didn't include support for .wmv and .avi.
The Mac version absolutely does edit DV-AVIs. In fact, it edits them natively -- just as if they were DV-MOVs.
But I doubt your editing software is creating DV-AVIs. It's likely using some proprietary codec.
There is a program called G-Spot for PCs that will show you your AVIs codec information. There is also a Mac program that will do this for free, but I don't know the name of it.
If you can find it and we can determine what the codec is for your AVIs, we may be able to figure out what to do with it or how to convert it to an editable file.
Meantime, you can try to put it in Premiere Elements, place it on your timeline and Share/Computer/MOV using the DV preset. It may convert the file into something you can use in an editing project.
It's likely using some proprietary codec.
Bingo. DivX. I downloaded/installed that codec and all is working.