Thought for a minute there you were saying I was barbeque'ing Vanguard. No, just calling a spade a spade, Vanguard is broken and X10 dropped the ball on its development a long time ago. Sadly, it looks like they used the same broken source code to create their iWatchOut plugin for ActiveHome. I'm just basing that opinion on the posts I read in the iWatchOut forum here. I think your best bet is to simply buy a multi-camera package and tell X10 to give you a discount for not bundling their software or their video capture device (since the driver for the video capture interface is only available via Vanguard install).
So here's my suggested setup...Get any camera package deal with motion detectors and a TM751 tranceiver, but remember that the color cameras only work well under ideal lighting conditions. Tell them to keep their software, video capture interface, and CM19A video transceiver and give you a discount. Use the motion detectors to do your camera switching. When you set them up, set them to send their OFF command after 4 hours (256 minutes, or 9 flashes on that part of the programming). Then get anybody else's video capture interface and the Argus Surveillance software from
http://www.argussurveillance.com and use its built in motion detection to filter out garbage so you don't get pictures of an empty room. I have mine set to 90% sensitivity, and the motion must be between 10% and 75% for it to send me an alert. Less than 10%, that's a picture of the dog or cat, I don't need to see that. more than 75%, that's snow in the picture from the cameras being shut off by the motion detectors after 4 hours of inactivity, I don't need to see that either. That's pretty much it, you have a reliable and dependable system after that.
If you want to be able to control the switching or positioning of your cameras and ninja bases, get the CM19A and I'll make my software available as soon as I'm positive that it's ready.