Some of this is about other Adobe products, but worth a read
As well as the below, right click the Encore icon and select Run as Administrator, which is NOT the same thing as running the computer with the Administrator account, and which fixes several "odd" problems... To create a two layer DVD (or a BluRay?), you MUST have Encore set to use the Run as Administrator option
Run as Administrator http://forums.adobe.com/thread/969395
-and Vista http://forums.adobe.com/thread/1021721
Odd Errors http://forums.adobe.com/thread/670174
Long File Names or odd characters cause problems
And This Message Thread http://forums.adobe.com/thread/665641
>exporting the video as an avi and then reimporting it
Wait... you ARE able to complete an export to AVI without error?
Why do you not load that AVI file into Encore for authoring?
Sorry, but none of those aply. I'm creating a single-layer DVD. I like exporting from Premiere since I find that it takes twice as long for Encore 1.5 to convert the avi. With my most recent mpg exports from Premiere it'll export the audio and video to the right time length, but because of the error it'll leave the last minute or two of video black even though there are no gaps and avi exports contain video during those last moments. Also I'm working with Windows XP SP 3.
>takes twice as long for Encore
Sorry, I have no more suggestions... but, if it was me and I could not solve the problem, I would use the process that works, even if it takes longer