Def. raise coming in. By limping and re-raising, you have 'trapped' the field in a biggish pot--with two jacks. I get sick to my stomach when I get 4 or 5 callers with aces. And look what happened, you put yourself in a bad spot on fourth. After having a hand you thought was strong enough to reraise on third, you are suddenly checking on fourth! On third you made the pot big enough so everyone was supposed to call, now you give them all a free card. Yikes. I don't mind checking on fourth to 'see where I am', or to get in a check raise to thin the field, but not after I have taken such a strong stance. I call the raise on 5th, Qs and Js are semi-dead, so a straight isn't a sure thing there.