Hiya Dave,
If you can access the camera from an IP in the browser that same IP should work within VDV. That being said, I am not overly familiar with the eyespy cameras, or any setup/configuration changes you have done to make it accessible outside your network. One quick suggestion I'm sure you've already played with - have you tried both the MJPEG and MPEG eyespy settings in VDV? You'll need to use the one corresponding to the video type you have configured your camera to export.
Another thing to try: If you're using one of the default eyespy configurations in VDV, it will be equivalent to opening the following address in another media player such as quicktime or VLC -
http://username:[email protected]/img/video.asfIf this does not work for you I would consider checking any settings you may have changed, or resetting your camera to default factory state and trying again.