Can a deferred sentence to county jail be negated if I revoke my probation and turn into prison time instead?

There is case law that says you can't revoke and go to prison but I think that may only apply to lifetime probation. Deferred jail means you don't necessarily have to go if you're doing well on probation so if I were you I'd double down on your efforts and try to avoid any incarceration.

I presume you are not currently being held. From what you posted you seem to think you are going to jail. Was jail time a condition of having the remainder of your time deferred? That seems a little strange particularly if you don't have to serve time until 2013. Typically a deffered senence only happens if you violate your probation. If you don't violate your probation then you should not have any problems.