according to Canons website the avi file is compressed with:
Movie: AVI (Image: Motion JPEG; Audio: WAVE (Monaural))
so you would need a Motion JPEG codec on your system, which you must have since your other apps play your files back. You might try downloading a new or different Motion JPEG codec and see if Premiere will import the file. At times Premiere and Vegas have trouble importing files. Years ago, Vegas 4 would not import a file compressed with Huffyuv, while Premiere would for me... so some times it just comes down to a particular app not being able to import a file.
You could also try Debugmodes Frameserver and frameserver the file from VD to P7.