WinAmp Update and Anti-Virus Programs. If you update WinAmp to version 5.54 (the official update of their website) - specifically it's 5.541 - your anti-virus program may kill it.
→[More:] There's been an issue with AVG and possibly Norton. I ended up deleting everything and reinstalling, which sucks, as there goes my playlists. You don't have to do this.
AVG, in particular, will read the file as a trojan called SHeur.CLZE in the zlib.dll file. It's not a trojan, and you don't have to worry, it's just the virus definitions in AVG snagging it.
From the WinAmp boards, here's a fix that works.
Temporary solution (until AVG fixes their virus definitions):
1. Re-install latest version of Winamp.
2. Right-click AVG icon in lower-right corner of screen.
3. Click Open AVG User Interface.
4. Click the Tools menu, then click Advanced Settings.
5. Click Exceptions under the Resident Shield section.
6. Click Add Path.
7. Navigate to C:\Program Files\Winamp (or the path where you've installed Winamp)
8. Click OK.
9. Click OK.
10. Run Winamp.