Do you still see any such issues?
These problems are most probably related to the Leap Second Problem that affects many servers worldwide since Saturday. I had problems with my servers during the last couple of days, and so did my customers.
Here is a little more info about it:
'Leap Second' Bug Wreaks Havoc Across Web | Wired Enterprise | Wired.com
Rolf
Which programs were left exposed? Anything with a Java component plus MySQL, Firefox, Thunderbird, and Debian, the latter causing server blades to ‘go dark’.
Mozilla, the organization behind the Firefox browser, also had problems.
"Java is choking on leap second," said Mozilla engineer Eric Ziegenhorn, who noted that some services using the Java software platform were malfunctioning.
Firefox was suddenly taking up a lot of CPU power showing nothing but a blank webpage, on all four computers. Closing and re-opening Firefox didn’t fix it, logging out and back in didn’t fix it, but rebooting the machines did.
Some google searching indicates that there was a problem with Firefox using a futex that got confused by the leap second, and getting into a loop.