OTA Rootkeeper seems to have kept root for me, but that doesn't help you much.
Use the link in my post to the XDA Developers thread. Deep in there somewhere others have had the same problem, and several reported success in manually restoring root. They post their steps. Good Luck!
Use the link in my post to the XDA Developers thread. Deep in there somewhere others have had the same problem, and several reported success in manually restoring root. They post their steps. Good Luck!