In ubuntu (12.04 now upgraded to13.10) my shift key doesnt work with some keys

[jokop]

in ubuntu (12.04 now upgraded to13.10) hitting combination shift key with some other keys dont type anything .(the right and left shift differ in the results)
here are the results of hitting keys "left shift key" with (in successive order) abcdefghijklmnopqrstuvwxyz.
ABCDFGHJKLMNSVXZ
here are the results of hitting keys "right shift key" with (in successive order) abcdefghijklmnopqrstuvwxyz.
ABDFGHJKLNSTY
how can fix it please?

[jokop]

continuing my thread,
want to add that maybe its not merely an ubuntu specific issue
I tried to run live-cd pmagic in my computer and there was the same keyboard problem
then I tried to connect the keyboard to another computer and it worked fine
then connected my keyboard back to this computer and also it worked fine so
I could have just tell you im satisfied but unfortunately the problem reappeard some hours later.
maybe after an ubuntu suspend I dont know
thanks in advance