I tried to add a private message to a project and associate it with a milestone. I got the error:

Query failed with message 'Table './smkeith_projects/ac_searchable_objects' is marked as crashed and should be repaired'

I also tried posting it without associating it with a milestone and got the same error. I've been using this install since December and never had this error. Help!

Try this: Open you database in phpMyAdmin, select ac_searchable_objects and then select Repair table option form "With selected:" drop down list. That should repair the table as instructed in error message you get from MySQL.