J1 to G4

[julienr]

Hello,

I am working in an American private high school with a J1 visa, in my last year. My visa expires in August 2009 and the way I choose to stay in the US and continue to work for this school is as spouse of G4. My wife has a G4. I know I will need a work authorization. But I have been told that I can not cumulate my J1 and the G4. So here is my problem: if I do all the process now and change my J1 to G4 as spouse and then start the process for my EAD, I may not be able to work in the US before getting the EAD. And if I wait until the end of the school year, in June, I may not have the time to get my EAD before the beginning of the next school year.
Is it true that if I get the G4 I will have to cancel the J1?

[Mr. Knowitall]

You can only be in status under one visa at a time.