Currently I am in L1B status and my VISA got expired on 16-Aug-2011. My company filed for extension and got the approved I797A and I94 till 16-Aug-2013. I will be completing my 5 years of L1B status through multiple visits by 04-Apr-2012 (have not continuoulsy out of USA for 365 days from my first entry), But my I-94 is approved till 16-Aug-2013, In this case what is the legal stay period?

Below is the my L1 VISA stay details for reference:
Entry: 16-Apr-2005 Exit: 31-Jul-2005
Entry: 16-May-2006 Exit: 16-Feb-2007
Entry: 04-Mar-2007 Exit: 06-Oct-2007
Entry: 08-Dec-2007 Exit: 23-Dec-2008
Entry: 13-Dec-2009 Exit: Current