We have no clue, sorry to say.
AE has had to accommodate so many different platforms, operating systems, third-party cards and such that the diagnostic process has become more and more complex. You may want to look here for the necessary information you should provide.
Having said that, do you know how are your caches are configured?
Please answer all of the questions on the page that Dave linked to.
Very likely, you are running out of RAM, so the cached frames are flushed from RAM to make room for other data.
We won't know for sure until you provide the information asked for.
The most likely cause is that it uses a specific plug-in that uses OpenGL or something like that and that there is a conflict with all this hardware acceleration stuff, but as the others said, we need to know a lot more...