I have a few questions for you,
1/ How do you know this card is running in ECP mode?
2/ Did you receive a utilities package for this card with the drivers
, the utilities package would possibly contain a program to change mode.
3/ "PCI ECP Parallel Port (LPT3)" is this reported in the BIOS or Device Manager?
I suspect that the card has an inbuilt BIOS where these changes are made I have tried searching the internet for answers but have found none
It may be that these functions change automatically, or as I have previously mentioned you may need a program that will allow you to do this in Windows. Lastly if the device shows up in Device Manager right clicking on the device may give you the option to change mode.
I hope this helps