Some ideas to follow up on.
How many PCI-e slots do you have? Try the one furthest from the cpu.
There are two versions of the card: 1.0 and 1.0.0.6. Can you see a version stamp on the card? If not, look in Device Manager under the Details tab & change the dropdown to Hardware ID to see if that helps. Also, in the Resources tab, is "Never use an interupt" selected?
I would download both
drivers from Rosewill, unzip them into separate folders and update
Driver in Device Manager starting with the 1.0.0.6
Edit: You slipped in an update while I was typing. With old legacy stuff, you need the printer to be on powering down the pc and before powering up. As to leaving it on overnight, it's only consuming a trickle of current; maybe 15 cents worth?