Just posted something on the other forums on a very similar question:
http://forums.na.leagueoflegends.com/board/showthread.php?t=2027428&page=2
Here's copy/paste from that post:
Like others have said, ward your jungle enterances if you know he's invading. He probably has timers on your buffs, so figure he'll come back 5 mins after the steal to continue his control. Team mates react faster when they see him enter the jungle.
Another tactic to think about, why did you settle for your own blue that game? The buffs are worth SO MUCH at lvl 1 and the optimal strategy is to always invade. I don't care if they have a blitzcrank or some other super cc, invade. More often than not, you'll find the other team sleeping and can just take their buff (you win jungle). If they invade, you trade buffs (you're even in jungle). And if you catch the other team moving as 5 (usually they don't move as 5), you either fight and get fb, or both teams back off and you clear your buffs like normal (you're even in the jungle). It always makes sense to invade.
Smart aggression wins games in the jungle. No need to sit back and be passive. That's always a losing strategy where the best case scenario has you coming out even if the other jungler is passive. Good junglers aren't passive.
EDIT: Another point. If your team is bad and not responding to the invade even with your wards, then don't even bother with the invade. Go take one of his buffs and his other small camps or go gank. If he's in your jungle, he's not in his jungle, and he's certainly not ganking. Use that information to counterinvade and stay even.
