Left shift key keyboard problem

Hello

I am having a constant problem with my new wired slim Mac keyboard.

When working online like this form, I try to capitalize a letter using the Left Shift Key, and many times it does not respond. this is often, as you just see i pressed shift to capitalize the "t" and "i" in this very sentence.

i have restarted, cleared the cache, run onyx fixes, etc. this happens only in web base applications and not with MS Word, etc.

Any ides < see it worked now? please help i make my living using this keyboard.