I have four homeplug (using the powerline spec) networking adaptors (85M Ebuyer own-brand).
I plugged in two and they worked. I used a linux tool (plconfig) to set a password on them - I could not get the windows 'PowerPacket' software to work - it refused to detect the adaptors at all.
This all seemed fine, the network worked perfectly, but now, it's started cutting out. They work fine for a few days, then completely stop working for a number of hours, then begin working again.
I have checked: The router still works, wireless and wired connections are fine. Nothing using homeplug adaptors can see the other side. Replacing both adaptors with the other two I have makes no difference (my first thought was overheating). Nothing in the house is being turned on or off at the time the homeplugs stop working.
It seems incredibly odd as nothing seems to be changing from when they work to when they do not.