Do I have to renew H1?

I'm going back to school in 9/1/06, however, my H1 expires on 7/31/06. Can I just apply to change to F1 now without renewing H1? or I have to renew H1 first, then apply for change status?

If I renew H1 then apply for change of status, the problem is: very possibly change of status is approved before 7/31/06. I wouldn't be able to work anyway at that time, I already change to F1, then what's the deal of renewing H1 first?

However, as I called several lawyers, they all say I have to renew H1 first.

Is it possible that lawyers try to mislead me because they want to make money from my H1 renewal?