Will I be able to change to Active along with my MOS?

Alright. I've already signed my contract for the Reserves for 8 years. I'm in the DEP and waiting to ship to Parris Island on November 1st, 2010. A recruiter told me I can't switch to active duty for 2 years. My other recruiter told me if I push it hard enough I might be able to make the switch sooner. But I'm not happy with my MOS, at all.. I'll be a Radio Field Operator. I just don't feel it's the right job for me. I wanted to be Infantry so bad, is there anyway I'll be able to make the switch of my MOS to Infantry when I'm also switching to Active duty? Thanks for taking the time and reading this, look forward to the answers.