This is why we always recommend against opening an older version project with a newer version of the program -- or at least saving a copy of the original if you do. This kind of buggy behavior is pretty common.
It's only the graphics that are flashing?
What are these graphics? Are they text or do they take up an entire video frame, like a slide? What program were they created in and how are they used?
Have you tried applying de-interlacing to them.
Did you apply any of the "Auto" Effects to the Clips? With varying lighting, many can cause "strobing."
In the meantime, can you tell us a few things:
- The Project Preset chosen at New Project?
- The Source Footage?
- Any Effects used?
- Desired Export/Share format?
- Where you are seeing this "flashing" such as when played in WMP?
The whole video from start to finish is flashing, there are many clips of stills and video footage which comprises of a 15 minute movie I have been working on. All was fine until I started using Premiere Elements 10. I havent used any effects, other than cross fade transitions from one clip to another. I am using a Canon HF200 as the source using a preset NTSC AVCHD which the Canon is a NTSC camera. I am exporting into Blu Ray, but tried sveral formats but its still the same. I have burnt a disc and the strobing / flashing is the same when played back on tv