H1B Filing date complication

[Sangeets]

Hi, I am currently working as on my OPT. My employer is filing for my H1B under general quota. However, the filing will only be done on 29th May, 2012 and my OPT/EAD expires on 7th June, 2012. I am worried about the real short time gap in between. What are my chances of not getting the cap-gap extension (specially the employment authorization extension) until 1st Oct, 2012 if the USCIS finds the H1B file to be incomplete upon submission? Will they consider the fact that my H1 was mailed out and attempted to be filed within my employment authorization period while granting the cap-gap work authorization? Please share any comments/ experiences that might be helpful.