Sticky Keys Windows 2003 server login screen

We are using terminal services on handheld RF guns. We are trying to user barcodes to log users into windows. Even though the Accessibility Options have all been changed, the sticky keys option continues to come up after we scan the user ID. I can repeat this same issue with a keyboard, so I know it is not a problem with the scanner or the barcodes.

I’ve seen instructions on some sites to change the flags in the registry from 510 to 506, but I don’t know if I can trust this.