请问小白兔,big problem from H-4 to F-1

I am under the H-4 since Janurary, 2007. Last month, i was admitted for the fall semeter, 2007. The school issue me an I-20 stating that my study program will start in August, 2007. I filed to change H-4 to F-1 last month. But USCIS approved unprecedently fast within 12 days. I received approval notice yesterday, which stated that F-1 is valid from 02/22/2007 and valid for Duration of Status.

Am I out of status because I can't take any courses between now and Fall semester? Actually, my study program starts August this Fall semester.

Is anyone has such experience? Thanks. Please email me to [e-mail]. Thanks