pocketcolud companion needs to be reloaded frequently

pocketcolud companion needs to be reloaded frequently

I have the companion loaded on 2 computers, and when its all working, can access them both fine from my iPhone. Very impressive, works beautifully. Then out of the blue my phone wont discover either device. I have to uninstall the companion on both devices and re-install. Both computers are running windows xp, only one has avg anti virus that I thought might be the problem, but that wouldn't explain the other one. In both cases the cloud and VNC icons are still in the sys trays. The computers are not being rebooted. I can't see a common link why i should loose both, they are even on different networks?
Any Ideas would be welcome. Thanks Lyn