Thanks Casey,
I realize everyone likes to get tons of info, was just looking to see if anyone has experienced this type of sudden change. The reason I didn't include all the codec info, etc is because it's been business as usual, then suddenly it stops importing correctly which is why I doubt it is any format or codec issue.
However - I'm using premiere pro version 6.0.5 and updated yesterday after experiencing issues but no change. I work on a PC, Windows 8.1. My routine has been pretty simple. I've been working in AE 6, outputting files to DNxHD, importing in to premiere and normally no problem. It may also import a file that didn't work on a second try or after restarting premiere.
In my mind, clearly a premiere issue. I did also do some conversions to ProRes using CINEC, also a standard procedure and it's had same symptoms with both before and after.
Eric