AAF , Tempo "varies" and Assertion Error, Import impossible

[joachim]

Dear members,

I recieved an AAF (24bit, 48kHz, 25fps) with embedded audio files, made with Media Composer.

Upon importing, the following error message comes up :
"Could not complete your request because Assertion in "..\ ..\ FF\ Audio\ FF_AudioFile.cpp", line 1000."

The individual references to audio files appear on my timeline.

In the workspace browser, there are no offline files, just the AAF itself.

Conspicuous : in the meta data of the AAF, item "tempo", it says "varies".

Could this be some "unrendered" pitch/elastic audio effect, some tempo change in the video edit session, that inhibts PT from importing, since it cannot guaranty synchronicity ?
How can this befixed by the video editor (by me) ?

Thanks in advance,
J.