I started off programming my Uno (2) on my Ubuntu 11.04 with no problems whatsoever. I was able to upload at will. Then one day something happened... I dunno what! My Uno wondermachine fell into the trap that I have now been reading about for a lot of hours. I can't open the port to upload my sketch. Lots of folks have had this problem. Some have solved it. I can't get it to work with any of the solutions I have read about: flash your firmware... been there, done that. No help. udev... tried that restarts, reinstalling, symbolic links... glimmer of hope, but then back to the drawing board. and others.
Anyway, what I DID manage to do was to get it running again on my Vista computer. I was asked to install the drivers when I plugged the card in. I found the drivers, but Vista couldn't see them when it searched for them. then I found a post in the forum that said to back up one level in the file heirarchy. It worked. Now I can program the Uno using Vista.
My point? It ain't the Uno at fault here. I don't think one needs to short anything out, flash anything or whatever. It seems to me the problem is in the way Linux is handling the COM port connections. And symbolic link does NOT work for me. Remember, my Uno USED to work (the same day, in fact) perfectly on the same computer, only to suddenly develop this bug. So what changed? Any Linux experts that can figure this out for the many users who are stuck? I don't know enough about Linux to understand what goes on, but I think that my reasoning is sound. I love my Linux computer, and hate to use the other one... It's not often one hits a tough spot like this with Linux, at least in my experience.