Hello,
I've tried to recreate the steps to install wpmu on http://syncslate.com twice and have run into the same problem. I'm assuming there are one or two things I've just missed. I can install it and access the backend just fine. I can view the public blog at the root domain just fine. But after creating a new blog called http://test.syncslate.com on the wpmu backend, I cannot access it on the front end. The first time I attempted to install it, the browser couldn't find the server. Second time around, I got the same error initially, then went into Blogs > Edit and checked to Enable Wordpress Mu Homepage Theme, and then got the Apache test page. I created a second blog at test2, and got the Apache test page without checking the theme enable box.
I created the wildcard DNS A record, which I would have assumed to be the issue. Based on what I described, I'm guessing that I'm missing a step each time, or doing one of the steps incorrectly. Thoughts?
Patrick