Multisite configuration problem

Hey all,

In my continuing baby-stepping Multisite adventure, I'm now unable to access my main site. I'm sure it's a simple configuration problem, but despite reading all the documentation at the WP codex and WPMU, I'm still really confused. Screenshot below.

Here's what I've tried:


define( 'NOBLOGREDIRECT', '' );

to wp-config. When that didn't work, I tried

define( 'NOBLOGREDIRECT', '' );

Previously, I was getting a 'page failed to load'-style error message. When I tried to reproduce it just now, though, I get the same screenshot below.

Any help would be awesome.