For those who bought the correct eBay USB/K+DCAN cable, & using the x64 architecture, Win 7, Vista (and even those with WinXP x32) that are having connection problems - I would recommend using the actual FTDI Drivers for that cable found here:
They offer Virtual COM Port Drivers for x86(32-bit) & x64(64-bit) in Win2000, XP, Vista, 7, Server 2003, Server 2008, & Server 2008 R2.
I would stick with the WHQL Certified downloads (v2.08.02) Release date 2010-08-11 that are available as a set-up executable file for EZ install.
>> When correctly installed, the appropriate USB Port will NOT show up in the 'Ports' section under Device Manager until the cable is plugged in to the computer - after plugging in cable, run DM and you will see the USB Port for the device show up.
I had no problems using the original drivers, but to make sure, I use the FTDI VCM drivers for my application (WinXP 32-bit).