We have the Welch Allen Digital 601 and I am unaware of any problems. My staff (lower IT skills than even me) loaded it, and it seems to be running fine on a laptop which WIFI's to our net running a server with Windows Server 2007. I don't like the image of the finished EKG in AC, as it is monochrome and the original on the laptop is two color and larger, but otherwise it is fine.
