A few of my users have upgraded to either OSX Leopard 10.5.1 or Tiger 10.4.11 as of last week. Ever since they have been unable to log in via the web interface. As some of these users are actually administrators I can confirm this affect both the user webmail and admin interfaces.
The error that appears above the username field on the login screen is attached. I've trawled the logs but can't turn up anything relevant or indicative of the problem, leading me to think this is something purely client-side.
Is anyone else seeing the same behaviour from OSX (Tiger/Leopard) after last week's security fixes?