A nějaké ovladače nebo obslužný software,kde by to šlo nastavit,jsi k tomu instaloval?
http://www.a4tech.nl/support.aspx?item=5560&key=#i tem
http://drivers.softpedia.com/get/KEYBOARD-and-MOUS E/A4TECH/A4tech-XL-747H-X-747H-Mouse-Driver-V1107V 26.shtml