Plextor PX-740UF Problems!

Hi im a having MAJOR problems using this DVD-recording drive.Here is what's wrong. .The DVD drive folder doesn't show up when I connect the USB cable,only after I disconnect it..Even if the folder is shown when I connect the USB cable every software It always stops. .It messes with DVD Shrink and various DVD Software (For example:When I turn the whole device on DVD Shrink refuses to work properly until I turn the device off) .Even if the file does burn (Nero 6) It stops during the writing process saying "There is no disc in the drive" When there clearly is. .The speed is supposed to be MAX yet it runs at 1x. .Even if the folder is shown when I connect the USB cable every software I tried never detects the device. Can someone help me this has become extremely annoying and im not sure how to fix it.

Make sure that all pertinent hardware and cables are USB 2.0 and not USB 1.1 ...

Oh so I must get a new computer (coming in christmas)