Not sure about needing extra drivers/patches... the system sees the device OK and it works OK on a printer. The system just doesn't see it as an LPT port - it sees the printers as a USB printer when connected through it.
But, I have found a PCMCIA parallel card that they say will definitely register on the system as an LPT port (and they are currently selling at reduced prices).
http://www.transdigital.net/info.htm
So I have lashed out and ordered one.
I suppose it'd be too much to ask for it to arrive in time for Lostock...
Fingers crossed now...
Al.