my wife has I-797A Approval notice with a I-94 together shows h4 valid from 11/01/2004 to 11/01/2007. she came back from china Aug.17th,2006 and got a I-94 attached on her passport that shows the date Feb 21,2006 due to her passport will be expired on Aug.21,2007. should she have hers I-94 corrected by a USCIS officer? is it ok if she ignores the difference between I-797 and I-94? thanks.