I-94 has only 29 days validity

[ariyer]

Hi All,

My parents came over to the US on June 14th 2012, they have a 10 year multiple entry visa. In the POE, the customs officer stamped their I-94 for only 29 days, until July 12 2012.

Can I apply for a visa extension (I-539) immediately (within one-two weeks of arrival) ?

[peace999]

Is it their first visit?
If no, can you post about their previous 2-3 visits .
dates and durations they stayed.