check similar cases...
Your problem is your I-94 validity expires.
http://immigrationvoice.org/forum/showthread.php?t=4155
http://murthyforum.atinfopop.com/4/OpenTopic?a=tpc&s=1024039761&f=7414019812&m=1691009731
Go to infopass and see what USCIS suggests and ask the possibility of approval of an amendment in your case.