Did you rush out and get yourself one of those new fancy-pants slim keyboards for you Mac? Those of you that have, be sure that all of your keys are working properly.
Apparently there is an issue that people are experiencing where the F3 and F4 buttons are not working at all. As far as users can tell the issue lies with the keyboards, and not the computers themselves, as the non-working units can be tested on several different Macs with the same issue.
Apple hasn't made any official statements regarding this issue. If they do, we'll be sure to let you know.
Apple's new keyboards not working for some [via tuaw]