I've been using HomePlugs to feed my Squeezeboxes, TVs, DS etc. for approximately 3 years and they've been completely reliable to date. I use a mix of TP-Link single plugs and Zyxel multi-port units.
Just in the last week I've started to have reliability issues with my network - weird stuff was happening like the wifi recycling every 2 to 3 minutes and having trouble logging into my EE router from my PC. Re-setting the router to factory default seem to resolve the problem for up to half a day or so then everything started going wobbly again.
Then, just yesterday, I did a factory default reset of the router and as I was trying to log into it, the router suddenly flipped from an EE log in page to a Huawei log in page. Weird as I don't have an Huawei router in the house, never mind plugged in. Access to the internet continued OK, but the devices plugged into the HomePlugs were not connecting properly with the network and the DS started doing that fading then coming back thing every couple of minutes which happens only when there's a network problem.
Removing all the HomePlugs and running only on wifi made the whole thing stable, but the hifi very quiet of course. I decided on a process of elimination by plugging in one HomePlug at a time to see which one was causing the problem. But this wasn't consistent - sometimes the problem arose with one device, then with another.
Then, the weirdest thing happened - McAfee on my PC popped up with a warning that I had about 10 devices on my network that "are not protected by McAfee". One of these was a laptop named "CHRIS". A Chris lives over the road from me! This only happened when a HomePlug was connected up - any of them - but not when only running wifi.
A bit of Googling later and I find that the general concensus on "leakage" of HomePlug signals beyond the house circuit breaker box / consumption meter has changed significantly compared to 3 years ago. When I first started with these things, leakage beyond the consumer unit was "extremely unlikely". Now, its reckoned to be virtually certain in an apartment block, and "fairly likely" in houses.
In order to make these devices "plug and play" they all present themselves to a default network grouping of HomePlug devices called "HomePlugAV". So any of these devices that stick with this default name will talk to each other. I think one of my near neighbours must've recently decided to use HomePlugs when they haven't before, and our 2 networks are talking to each other. And because many routers default to the same network IP address, I was getting access to my neighbour's Huawei router. For some reason, that was "over powering" the IP address of my own router.
So not surprising that my HomePlug devices and the rest of the network was getting confused - the DHCP server and default gateway were probably flipping between my own router and that of my neighbour.
So the resolution was to install the HomePlug management software on my PC and rename the network name on all the devices away from HomePlugAV and to something unique to my own house.
Now all seems to be well and stable - across HomePlug and wifi. Will keep an eye on how it goes and I have a list of the MAC addresses of the outsider HomePlugs so I can go and advise whichever neighbour they belong to to secure his/her own network.
So there you go. Take note and make the changes to your own HomePlugs before things start to go a bit wobbly in your network too.TP