Error validating access token

I have linked posts successfully to Facebook in the past, but keep getting this message:

Get me: Facebook error: Error validating access token: Session has expired at unix time 1341525403. The current unix time is 1361307290. @ 2013-02-19T20:54:50+00:00

It appears to be a Facebook error. What can I do?

http://ww.wp.xz.cn/extend/plugins/add-link-to-facebook/