Well Chris, you're getting your chance to help me out :-( After functioning perfectly well, I shut my mac down. An hour or so later my wife came home from work. Proud as I was (the fool) I wanted to show off my achievement. Guess what happened..... Same thing all over again. Repeating keystrokes. Aaarrgghh!!!
After some serious cursing I continued investigating. I turned on my laptop (windows) with Plex in the livingroom. Same problem with Flirc. Repeating keystrokes. I went upstairs to the room where I configured Flirc previously. No problems there.
Then I went back to the livingroom and turned off all my equipment (TV, home cinemacenter and decoder). Flirc performed fine. That narrowed it down. Then I turned all of the above one by one on. Bazinga! My Philips TV (32PFL7404h) seamed to be the little bastard that is the cause of repeating keystrokes.
Now what is strange here, is that in the afternoon (daylight) it was working fine with my TV on but when it became dusk it didn't. So it looks like it has something to do with lightconditions. The big question here is how I'm gonna solve this one because frankly I'm stuck for now. Chris to the rescue please ;-)