Database Problem

.72 Beta 2 on Mac OS 10.2 has been running great until today. After a routine server reboot my blog is hosed. I get these errors:
1. SQL/DB Error --
2. [Can't create/write to file '/var/tmp/#sql1c1_32_0.MYI' (Errcode: 9)]
and
Warning: Invalid argument supplied for foreach() in /Library/WebServer/Documents/blogkc/b2-include/b2template.functions.php on line 1085
The weird thing is that this only happens in the public interface. The admin interface is fine, I can still edit and add posts. Permissions on /var/tmp/ seem to be OK (drwxrwxrwt), and other PHP/MySQL apps are working just fine. The only problem is the one part of this one app.
the URL is http://blogkc.com