(PECL mongo >= 1.0.0)
Caused by a query timing out. You can set the length of time to wait before this exception is thrown by calling MongoCursor::timeout() on the cursor or setting MongoCursor::$timeout. The static variable is useful for queries such as database commands and MongoCollection::findOne(), both of which implicitly use cursors.
Salocin.TEN (2012-08-26 22:39:55)
If you wish to turn off timeouts, do...
MongoCursor::$timeout = -1;