"can't write to disk" error – can't update WP

Started getting en error trying to upload images:

http://cl.ly/image/2l1Z2b2w3y1w

Called my host, MediaTemple, and everything checks out.

They had me update the php.ini file, but other than that they were confident this was a WP thing.

So, I tried to update my plugins and got a similar message. I then tried to update to 3.7 and received this error:

http://cl.ly/image/1A2F0G3s1o1q

wtf.

So, MediaTemple did some other stuff on their end and now getting this:

http://cl.ly/image/022b0o3C0p1g

HTTP error…

ugh. Anyone?