Makaveli6103,
I am using powerline adapters (Devolo) around my house and am not having any issues....now......
I don't know anything about your specific pieces of kit, however, when I first started using them I purchased a pack of 2 and did not have any issues. Then I purchased another pack of two around 6 months later and started to have all sorts of funny things going on. Even though the two purchases were of the same model number, they were a slightly different firmware revision, yes, these little gems are programmable. I had to download new firmware and use a special program (supplied by Devolo) to load the new firmware on to all of the adapters so they were all the same level. You also need to sync them so that they all know they are on the same network (I think that's what it does anyway)
Also, these units are VERY tetchy about being used in an extension lead, i.e. a 4 or 6 gang. The documentation I have read states that it does not work. I know it does, but the throughput is not a good as a direct connection to the wall socket. It works for what I want though and that's enough for me.
Hope this helps.