I got this email from Betfair:

Planned site maintenance on Monday 20th February

Sports Exchange unavailable between 6.45 GMT - 8.45 GMT

Poker, Casino, Exchange Games unavailable between 6.45 GMT - later in the day

Please be aware that there is essential planned site maintenance and upgrade work scheduled for Monday 20th February 2012 starting at 6:45 GMT.

From this time our Sports Exchange, as well as our Casino, Arcade, Poker, API, Community and Mobile products will be unavailable. We anticipate that the core exchange will be back up and running by 8:45 GMT on Monday 20th February.

The rest of our products will be available later in the day.

The upgrade work is being undertaken to bring long-term benefits to our customers and we will be working hard to get normal service resumed on the site as quickly as possible. We'd like to apologise in advance for any inconvenience caused, and thank you for your understanding. Updates during the outage will be available at service.betfair.info.

If you have any questions then please email our Helpdesk at info@betfair.com.