well, I dont know what to suggest then...maybe u should ask for support at The AppServ site?
ah...wait..if u are running webserver with PHP on your comp or atleast have shell access to the server, try to see if zlib.output_compression is set to on, or/and extension=php_zlib.dll is uncomented (extension=php_zip.dll on PHP v4.3) in php.ini file (on windows in: c:\windows or c:\winnt )