QUOTE (DVDdoug @ Mar 31 2009, 14:26)

Most audio editors use floating-point storage, which gives you unlimited headroom. But, most file formats use integers. So, you can end-up introducing clipping when you save. Once the file is clipped, it cannot be properly restored.
A loating-point file exceeding 0 dBfs would sound terrible when played from Audition as well - the peaks would get truncated on their way to the sound card. And Audition may save files to 32-bit floating-point wave that would preserve that information.
We definitely need more data: which area of the program are you saving from (Edit View vs. Multitrack View)? To what format? And checking levels with Amplitude Statistics wouldn't harm.