My Pagerank is back

Since posting last July 22 that I noticed my pagerank vanished and only showed as “No PageRank Information Available”, after doing some investigation on my files I saw that I had an empty robot.txt file, so I added the allow tag back. This could be the culprit,  it could have caused googlebots to not crawl the site.  Now I need to investigate why my robot.txt suddenly became empty. Anyway thanks google for giving back my PR 3/10.