Plex, why is this so complicated!?!? DLNA, Panasonic tv

I´ve tried your software so many times, I love the UI, but I never can get it to work.
Everything was working right with the PS3 Media Server, DLNA and my Panasonic Viera 42AS600. I tried before Plex and gave up on it because I just could get it to work. But after some Java update (I guess) my PS3 Media server don't work anymore, so I went back to PLEX and give it another try. The Tv can prompt me with the Library in the Media Server, but every single file is not supported. :/ After that I tried Twonky Server, and it works, but I hate it and the UI is terrible. You guys have a great Media Server here, but... is it so hard to stream a file through DLNA without issues?!? I tried the web app in the TV Browser but it's impossible to use, and that on the browser side. Please give me an hint here? I lost all my hope already. By the way, I am using a 1 GB ethernet cable.
thanks in advanced