Thanks, davidgary73. Support at Access were wonderfully prompt. However, the damn thing doesn't actually solve my problem.
Or any of my problems. Although I can happily connect via midi backwards and forwards, whatever I try to use to send midi control files or sysex files doesn't seem to recognize the Virus.
So, old copy of Cubase. Someone has made a very nice panel that controls the existing patches really nicely. What it won't do though, is accurately list the patches that are stored, or send replacement patches.
Similarly, I've been trying to update the OS. Cubase seems happy to send the midi file. Virus doesn't seem to want to recognize that a file is being sent.
I guess I'm in for a whole lot of trial and error, but thanks for your help. I really appreciate it.