I recently purchased a second Posideon Z keyboard when the first one I purchased for my Linux box worked so well, I had to get a second for my gaming/programming rig. Everything seems to work great on it, except when I am programming. I have a tendency to lean pretty heavy on CTRL key combinations when I work (CTRL-S, CTRL-Z, etc) and I've noticed that it appears that the key doesn't always work when used in conjunction when another key. At first I thought it was a driver issue, but now I am leaning to the idea that the ctrl key is bad.
The behavior I'm seeing is that when I hit CTRL-S, rather than sending the command to the application, an 's' is typed. Then I'll hit ESC, and hit CTRL-S again, and then the application will save. I thought it was just that key combination, because I had not seen it any other key combination before, but then last night, I saw it when when trying to undo something (CTRL-Z).
I don't see the issue on my Linux box, but I've not done nearly as much programming on it, and I rarely hit CTRL keys on it. I'm tempted to switch machines in the interim, but I thought to check on support, see if there is something I can do, rather than send in for an RMA.