I can't fault you for check-raising (though a lot depends on the nature of the pre-flop raiser and the stacks), especially after a 1/4 pot bet. You have to make the mediocre draws pay/fold since so many two card hands dominate your draws. The vast majority of the time you're at least 50/50 here IF it goes heads up. The exception, of course, is when he pot raises back at you ...

The big question for me is what kind of hand would UTG+1 play this way with. My opinion is that he is either well ahead, or an idiot. The latter is a real possability at these limits.

Your biggest fear is a set plus a better flush draw, in which case you're beat at least 80/20. More realistically, you fear a better flush and str8 draw. A hand like 9s Tc Js Qc has you beat 65/35. Just, if not more, likely though (at these limits - on pokerstars anyway) he has a set. Against TT or 88 you're about 50/50. You have a 65/35 advantage over 44. You're also about 50/50 against AAxx suited in spades.

I'm curious if anyone folds to the re-raise against some/most/all opponents when the stacks are deep. Since I don't play deep stacked very often this is usually an easy call for me.