A few months ago I traded some hardware for a used Logitech MX keyboard and mouse. I used this set for a coupe of hours and it soon died on me. Not knowing the source of this equipment I called Logitech and after several tests I got an RMA number and within 2 days I received a new and more expensive set because the old one already phased out. The new set didn't work too well. Some times it lost connection but did reconnect properly. Because I can't live with hardware that fails once in a while I've sold the mouse and stored the keyboard, because the mouse did not lose connection at all. I didn't contact Logitech again because I didn't want to. I'm sure they would have helped me out again. I got a new LX500 from a local shop and this is as far as I could see the most competitive cordless set from Logitech. I used this set happily for 2 weeks and now the keyboard went dead again. It first starts missing keys, and it's behaviour is like the PC is responding very slow. Then holding a certain key results in a moment of silence 1-2 seconds and then printing that key about 8-10 times on screen. After 2 new desktop sets experiencing this kind of trouble I got mad. I checked the batteries, but the batteries in the keyboard still work with the mouse. The result is that the LX500 keyboard is died in 20 minutes and now I'm confused. Expecting that Logitech is a quality vendor, prooving with 5 years of warranty. On the other hand I don't believe that I'm the lucky one to receive 2 sets with a troublesome keyboard and a dead keyboard. Also my first set had similar behaviour but was more then 2years old. Do you as a Logitech cordless user ever had trouble with hardware failure? Or is it just bad luck? One thing I'm sure about, I have to call Logitech and they gonna have it from me.