Recently in a SharePoint project I ran into a bunch of problems with a faulty installation. I've blogged about a few problems I've had with it, but most recently I ran into a problem where the Search box on all my sites just disappeared. I was at a loss as to how it happened, it was there one day, and gone the next. I narrowed it down to the fact that I had been messing with the SSP recently. Turns out that the user I specified in the SSP to connect to the database didn't have permissions on the database itself. I gave the user permissions on the database server and after that, the search box reappeared on all my sites.