Looping problem with Sound Forge 7.0

["Chuck Scholtz" <opbeachguy@hotmail.com>]

After I highlight a portion of a .WAV (or MP3) file in SoundForge 7.0 and 
do
a "Trim/Crop" to get the loop just the way I like it, the saved file always
gets a bit of silence inserted at the begining and a slight fade appended 
at
the end.  I dont want this, and I am trying to get rid of it so I have the
exact file I have edited.  I looked under "preferences" but I cant find any
setting that will get rid of this.  Any ideas what I am doing wrong?