I have the same issue only the key for me that works some of the time is the left selection key or Menu. Makes it hard to unlock the phone when I want to use it. Let me know if you find a fix.
I am having the same issues. The keys that does not work for me are 3, 6, 9, calendar button and the unlock function key. If I keep pressing the keys it makes no difference and then they will starting working again. This goes one numerous times througout the day to be a big problem. I am having my phone replaced by my service provider but will I be having the same problems with the new phone. When this first started my unlock code used a couple of those button so imagine my agony when I trying to get something done. When this first started I thought the phone was frozen as I wasn't able to unlock the phone - so I would remove the battery. It was a couple weeks later that I realized that the problem were with the keys themselves.
I have the same issue as Siron.. I'm very frustrated at this point. the same keys u mentioned are the same keys that i have a problem with. How could it have been a hardware problem and it just so happens that we have a problem with the exact keys? What exactly did u do to correct this problem?
I am experiencing the same issue with the z-m row of the qwerty. I find occasionally if I hold down the key, it works. Also, I find that sometimes going backwards from "." then "," then "m" to the desired letter, then erasing the nonsense works, but this is a silly workaround in the longterm.
I find that it's only the letter z-m and the numbers 7-9 that are causing the issue.