Hi Jeff,
I use a custom preset,it ranges from 5 to 7 mbps cbr depending on the length, quality 4, no changes to GOPs.
I use mainly DV clips but occasionally .wmv or whatever the customer brings.
I tried exporting from AME as a dv.avi and that worked in Encore. So then I tried the same clip as .m2v and Encore liked that!! Tried another clip and it seems things are now working fine.
The only thing different from yesterday was fiddling with AME export settings to try your DV test request.
Love a mystery!