Audition is 'auto-trimming' files that are dragged intro a multitrack

Has anyone found a resolution for this?

I just tried experimenting a little: 

1) I drug the same .mp3 file into the multitrack from Finder and could repeat the trimming issue.

2) If I left the .mp3 file in the files pane, and drug it from there, there was not a trimming issue.

3) If I removed the .mp3 from the multitrack and files pane, and added it again, the issue would be present.

4) Converting the file directly to wav and importing - no trimming issue.

Here is a view of the wav next to the mp3:

The multritrack mp3 clip can be 'extended' using the trim tool but considering it's a couple of seconds, it's hard to see on a hour-long mix (we push out a couple hundred mixes in a couple of days, so having the guys pay attention to this slows things down a good bit).

I feel that this has been intermittent for a year or more, but has been consistently an issue for the last few weeks, if not longer where we did not notice.

If you try to decode one of these MP3 directly into Waveform view, what happens to the start then on the Wav file that's created? And if you move this file into a multitrack session, does anything alter about the start?

You have to bear in mind that you can't 'open' an MP3 file in Audition directly - it has to be decoded to Audition's working format, which is Wav. What I'm not sure of in the present MP3 encode/decode environment is what is happening to starts and finishes. The reason that I'm not sure is that at some stage in the relatively recent past, the encode/decode engine was changed from Fraunhofer to LAME...