u sure you got the correct driver? .. one suggestion is go to system properties, hardware tab , click on device manager, expand your Ports entry and double click the Printer Port LPT1 and see what the device status says... go thru the tabs to see if you can spot something peculiar... if the device status says it is not working properly then perhaps click Troubleshoot and see if you can resolve this.
all my printers are usb except and old hp6L whisch is conn to the parallel port like yours and under port settings tab it never uses an interrupt and under resources tab it uses auto settings and there are no conflicts... perhaps check that also on yours .. let us know how you go ... rob