I'm so so sorry if what I'm going to ask is an stupid question but, maybe....<br><div class="gmail_quote">Do you have the feature Sticky keys activated? because this feature produce the same behavior you are describing....<br>
</div><br>You can check it at: systempreferences->Accessibility->Modifiers Keys<br><br>(It could sound stupid, but it happens to me at gcds).<br>