Problem solved for me anyway. Another Apple thread suggested using Quicktime 7.7.1 instead of the newest version. The only problem is that version does not show up on the Quicktime site and the next earlier version available is 7.6. Version 7.6 played video but dropped frames and was not useable. It has something to do with a progressive vs. non-progressive codec file. Anyway this is an easy fix.
This is for PC Windows 7 not sure about Mac or other Windows versions
1. Go to control panel in Windows and find programs and features. Find Quicktime, highlight it and then go to the top and select uninstall or change program. Uninstall Quicktime
2. Go to this link http://www.oldapps.com/quicktime_player.php?old_quicktime=6769?download If you prefer to look at the website before downloading go to oldapps.com and search for Quicktime 7.7.1.
3. Download this version of Quicktime and you will be good to go. Quicktime and my editing software (Corel Video Studio Pro X5) all work fine now.
Life is good again.