This suggests that there may be a file that has a sample rate stamp of 48k, for example, but is actually 44.1k or there are files with mixed sample rates in the Pro Tools session that is being imported into AV.Pro Tools will allow you to import mismatched sample rates into the same session, the playback speed/pitch will be off on the files that have sample rates that differ from the session sample rate but they will play.AudioVision/Media Composer will not allow mismatched sample rates to co-exist in the same project/sequence.