Last night was pretty slow for a lot of people due to the event, if it's Cyrodiil it can be a common and frustrating problem due to performance issues.
If you haven't already create a bug report with as much information as possible, the more information they get on why and how it happens to different people the easier it will be for them to track down any issues.
@Turelus - EU PC Megaserver "Don't count on others for help. In the end each of us is in this alone. The survivors are those who know how to look out for themselves."