There are huge problems with older dongles, since they were designed at a time when all software designers thought they could play directly with the PC hardware. So they all did lots of tricky stuff to try to hide their dongles, in attempts to make the printer or serial port still work with other equipment.

These tricks normally fails when accessing the ports through a standard Windows hw driver, since that driver does not export the raw pin signals, but instead just export the service to communicate. Alas, some companies just deserves to get their copy-protection system hacked because it hurts the paying customers too much.