I assume mecharujirou used the normal way to check the WA version, clicking on "Nullsoft Winamp..." in the main player's context menu.
The main site has been having random problems recently. Not downloading anything or downloading the wrong version of stuff.
Winamp Pro 5.666.3516 fully-patched - Komodo X Touchscreen by Victhor skin
Windows 10 Home 64-bit desktop - Logitech Z906 5.1 speaker system