past 5 months there is no pr update. Why? see the last page rank update history below. Google updates Toolbar Pagerank every 3 or so months: 4 February 2013 7 November 2012 2 August 2012 2 May 2012 7 February 2012 7 November 2011 1st Week August 2011 JULY 2011 JUNE 2011 JANUARY 2011 April 2010 Dec 31, 2009 30 October 2009 27/28 May 2009 June 2009 1 / 2 April 2009 30-31 December 2008 27 September 2008 26 July 2008 29 April 2008 9 January 2008 26 October 2007 28 April 2007
You can never know with G. They do what they want when they want. Nothing is ever predictable. Just keep doing your thing and don't worry about it. PR updates don't matter anyway.
I have heard Google not interested in updating PR. Tired of updating. They need some sleep. So google will give way to DA (Domain Authority) and take some rest. You may have heard about tortoise and hare story.