I receive the following errors on all of your wep pages.

Warning: file_get_contents(): SSL operation failed with code 1. OpenSSL Error messages: error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed in /home/boinc/cpdnboinc/html/inc/header.inc on line 9

Warning: file_get_contents(): Failed to enable crypto in /home/boinc/cpdnboinc/html/inc/header.inc on line 9

Warning: file_get_contents(https://www.cpdn.org/menu_boinc.xml): failed to open stream: operation failed in /home/boinc/cpdnboinc/html/inc/header.inc on line 9

There is more information in the "site Problems" section of the Number Crunching thread.

A temporary fix for the BOINC server code is simple but does rely on access to the servers as Oxford have locked things down so as to keep things secure. In essence it is just replacing the certificate bundle that requires replacing in the Windows version of the client.

I expect that seeing as while annoying, it doesn't affect the functionality of the site, they will wait till a visit is needed for another reason or possibly even till an official server code update fixes the problem.