My computer ( Dell Optiplex360 w/ Windows Vista Basic ) has been supporting my homeworks software for years with no upload problems. Suddenly the controller will not accept an upload & displays the message: "proc1.dat unsuccessful", or "dsp_kernel.s (1/27/2005 01:11pm)". Download seems to work fine and the wall units flash when attempting upload; they then time out & return to original program. Can you tell me how to resolve this issue?