I have the same problem, but I don't know if it's for the same reason. Since your problem is solved, I'm going to threadjack instead of starting a new thread.

I just moved to a new web host (medialayer), and I have the same problem. configure.php is 444, but I am still getting the writeable message. I suspect it is because medialayer uses phpsuexec and all scripts run under the domain account username instead of 'nobody', so the files in my folders will always be writeable by the script, no matter what permissions they have. If this is the problem, how do I get rid of the warning? If this is NOT the problem, what else could it be?