VAG-COM reports: no response from controller

Hello everyone! I own a GOLF 4 (1J). I recently bought this OBD connection cable on eBay: http://cgi.ebay.de/ws/eBayISAPI.dll?… I know… eBay eBay…. but now my first questions are coming: Is there also USB OBD connection cables or interfaces on eBay that you can be satisfied with? Can anyone report on experiences with such things http://cgi.ebay.de/…mZ8065311496QQcategoryZ30921QQrdZ1QcmdZViewItem? Now comes the second question regarding I have tested this cable today with the “probe version” of VAG-COM, namely with the 311.2 . The cable is recognized and the drivers are installed, VAG … so far it also recognizes everything well. But as soon as I want to manually read out individual ECUs or sensors I get almost 90% of the whole selection {no response from controller – retry?} or similar. As said two three things can be read out but otherwise… Can this lie on the cable or is that always so who n VAG-Com is not fully unlocked or registered? I think I have only 6 – 8 pins at the OBD cable end. Does that have something to say? Do all 16 pins normally have to be there? Would I also be very pleased about few but competent answers. Thanks in advance! MfG Pavel