Installed USB printer, now LPT1 no longer communicates

Prior to installing the drivers for my new USB Samsung Color laser I
could communicate through the LPT1 port. I'm using an ISO programmer
to program electronic ID cards.

After installing the drivers for the USB printer, I can no longer
communicate with my ISO programmer. The LPT port is still there as XP
still recognises it.

I've tried to install a new printer driver for this port, to no avail.
I don't have an old printer to test on this port.

The only thing I haven't tried is to uninstall the USB driver. Any
ideas that doesn't involve removal of the Samsung drivers?

Thanks