External USB DVD-RW

Hi I bought a new USB LG E60N external DVD-RW to use on my Fujitsu Siemens Amilo Pro laptop which is running Win XP SP2 and has all current Windows updates downloaded. The laptop is not quite 3 years old. The new USB DVD-RW will not read any CD or DVD discs. I get a no disc in drive error message. I have checked the device manager and the new DVD drive is listed there ok. If I right click on the new DVD-RE icon in my computer and go to properties, then the hardware tab it says the drive is working properly, however on the general tab and with a good cd in the unit it displays 0 bytes. I have also checked the recoding tab and made sure the two boxes are checked. I am plugging directly into the main laptop USB ports, which also sees my portable HD ok.I checked the DVD-RW on my desktop pc and it works fine so it is not the unit so has to be something on the laptop. No new software has been installed recently. I was using Roxio as my DVD burner and thought that might be the problem, so uninstalled, but still won't see any DVD's or CD's. Have looked at Microsofts site but no joy.

Any advice would be very welcome

Nick