What to do when a maniac adjusts to you?

[Alpha13]

I play 1/2 6 max and always looks for games with maniacs or super LAGs, especially when I can sit on their left. When I can sit by these guys they become my target as I focus most all of my attention on them. After a while they catch on to what I'm doing (isolation raising with weaker hands, never bluffing, etc) Then they adjust to me, either becoming more tricky (smart LAG) or a little on the weak side. When this happens I generally leave the table because the LAG does not spew as much, which sucks because the crazy ones are hard to find around this time. How do you keep these guys from tightening up and playing better?

Thanks