Issue with updating program from 5.0 to 6.0

I was called to look at a program I had written in 5.0. They said that the video stream had a glitch and that text behind the video stream was flashing through the video stream image. After a few hours of observing the issue without success I reverted the program back to 5.0 and the program worked as designed.

The program was designed for various machine set-ups, (i.e. if there is one or two cameras, if it is a forklift or a container handler or both etc... various screen options are turned on or remain unseen in the background).

In this bug a video Rear-view Mirror video stream should have been turned off due to the machine set-up. The area used by the Rear-view Mirror stream would be replaced by information regarding the condition of the handler. If the screen went to a video page, (once), and returned back to the screen that had the turned-off Rear-view Camera image, the video image would be displayed and information that should be displayed was covered up. A flashing message would flash through the unwanted video stream with every pulse. Only cycling power would reset the logic. 

Reverting back to the native firm-ware fixed the issue.

For whatever reason updating the Rev-level of IQAN-Design caused the issue with how and when the video stream is displayed. Possibly if I removed the troublesome logic when updating the firmware and re-wrote it in 6.05 this may have worked fine but I did not try this.

Have you noticed similar issues with logic is translated/mapped during firmware updates?