Thanks for your response. I am not having any issues with HD 1080 files from my quadcopter and my GoPro Hero 4. This only applies to files from my Canon FS 200.
1. I am using Premiere Elements 13 on a Win 7 machine with 16 GB RAM and an i5 processor.
2. No, the properties of the imported files in Premiere are 540x480.
3. The source video is 720x640 16:9 29.97.
4. Camera is a Canon FS200 set to 16:9 highest quality record, which generates MOD files - again read without modification by MoveMaker. I did change the file tag to MPEG on some other files and they played fine from Windows Media Player and MovieMaker.
5. MovieMaker reads the files directly from the camera at project settings at 16:9.
Appreciate your help.