My directory become N/A too, http://www.adulu.com/adulu/directory/ but the directory have traffic and indexed on google not be banned.
I think this pr update was not accurate many sites left out without changing the pr. and i found just domain which is in underconstruction got pr 1 , 2 , 3 or 4...
Don't cry. I'm in the same position with two of my sites. PR4/PR5 internal pages, but suddenly the homepage became N/A