What do you do about behavior issues away from you?

Thanks for the reply. I sent a big box of stickers to school a couple months ago and the teacher is supposed to reward him with a sticker for every "good" thing he does. She has been very inconsistent about actually doing it and she's tried it again recently but he has no interest. We don't do much at night during the week because we both work full-time so there really aren't any privileges to lose during the week. I really hate doing a "future" thing like telling him he loses TV or Legos or whatever on the weekend because he doesn't really understand the punishment if it's not something done ASAP. We've done several different incentive systems and they do work but only for a limited time. I've been thinking I need to come up with a new one to try getting him through this. Not sure what. We've done stickers, charts, rocks. But that will require the teacher's full participation, and I think the stickers aren't working because he lost interest when she wasn't doing it consistently. Arrgghhh, this is frustrating!! Side question - is Firecracker still on meds? I read about your problems with the first one you tried and I've been wondering if you've tried anything else or not.