Tigsounds - strangely enough I had tried similar to that yesterday with the USB0002 port as I already have another printer connect to USB0001.
Anyhow, I changed to USB0001 and did note that when I unplugged/plugged-in the USB/Parallel adapter the port status did update.
I then changed my Lexmark back to USB0002, forced a reset of the printer and it works now.
Thanx for the suggestion.
(BTW, it took me a few moments to realise that I didn't have a small insect crawling about my screen and that it was part of your post footer...at least I hope it was, otherwise I have some creature wandering round my house at the moment!)