Cameras can be a big pain the ___! There are so many variables to getting them to work. Most users can get a 3 camera system to work with no problem. (most of the time) But getting 4 or more can be quite the chore.
I don't know anything about the vanguard software but I do know a little about the wireless cameras. The antenna of the receiver is really directional. I my self bought a Home Security Camera that came with a receiver/dvr/vcr commander with 4 channels, and it so happened that my x10 system was capable of showing on one of those channels. So now I have a good receiver with a omni directional antenna.
So many items interfere with these cameras so making them work 100% is null and void. Cordless phones in your office or home, microwaves, anything that runs on the same 2.4 frequency will really give you problems.
Noise and signal suckers will frustrate you to no end! Cameras won't switch, cameras won't turn off because something is blocking or sucking the PLC going to the cameras.
Phase issues. I'm sure you know what this is having x10 in your home to control lights.
Some things to try: put antenna totally flat with the ground pointing up. (i know you didn't want to here that) But that is the only way I was able to receive all of my cameras.
If you have the money buy a different 2.4 camera with a receiver that has 4 channels. Most of the time you can get the receiver to pick up the frequency that the cameras are on by adjusting the frequency on the cameras and receiver.
Make sure no noise and signal suckers exist. Start unplugging and see if the cameras work better, if they do than you probably need some noise filters.
You didn't say what transceiver you were using to switch the cameras, but I assume it is the cm19? If so the range on this thing is very poor. There are some modification for the antenna, just do a search here on the forum. You also might want to get you a v572 transceiver. You'll never have range problems again.
http://www.wgldesigns.com/v572.html I personally have one of these baby's and I couldn't live without it!
Software: For some reason the AHP and Iwitness software that I use is a cpu hog when recording video and just doesn't work the way I want so I'm making the move to Blue Iris. You might want to check this out for you.
http://blueirissoftware.com/But after all this you are right. The price is right. But..... is still need to do some things to make it work right. I'm not saying that all users had to buy a phase coupler, noise filters, different transceiver, plc amplifiers, different software, but I did.
I hope this gave you some ideas to check. But sure the guys and gals here at the forum can solve any of your x10 challenges.