First, you've incorrectly started a new thread in the "soon-to-be-archived-only-for-legacy-support" Winamp3 Tech Support forum. You do not have Winamp3. You have Winamp. A completely separate product. More specifically, you do not have Winamp3 v1.0. You have Winamp v5.0
Anyway, in Winamp 5.0, try this...
CTRL+P to open preferences > Plug-ins > Output > DirectSound output v2.2.8
Go to the "Other" tab and under "Silence remover" check the checkbox to the left of "Remove silence at the beginning / end of track". Also move the slidebar to change the Cutoff threshold if necessary. You may also need to change buffer length under the "Buffer" tab.
OK. I'm now moving this misplaced thread to the proper forum.
See this main forums page screenshot of where to place all Winamp 5.0 related posts...
Winamp 2 forums will be renamed simply to just Winamp forums very soon (to also include Winamp v5.0), as soon as Winamp 5.0 Final is offered as the official download at Winamp.com (as soon as Winamp3 is no longer offered for download and becomes an unsupported legacy product)