Too weak tight with JJ?

[Shorty35]

Was this weak tight; or a solid conservative play early on. I decided to play the Jacks for set value from early position. And then didnt bet the flop (mistake?) figuring that I would get unpredictable action from overcards (or worse, and overpair, which seemed very possible). The involvement of the big stack obviously also influenced my thinking.

PokerStars No-Limit Hold'em Tourney, Big Blind is t30 (7 handed) converter

saw flop|<font color="#C00000">saw showdown</font>

MP2 (t1600)
CO (t5005)
Button (t690)
SB (t1410)
BB (t1605)
Hero (t1995)
MP1 (t1195)

Preflop: Hero is UTG with J[img]/images/graemlins/heart.gif[/img], J[img]/images/graemlins/club.gif[/img].
Hero calls t30, <font color="#CC3333">MP1 raises to t120</font>, MP2 folds, CO calls t120, Button folds, SB folds, BB folds, Hero calls t90.

Flop: (t405) 4[img]/images/graemlins/diamond.gif[/img], 7[img]/images/graemlins/spade.gif[/img], T[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, <font color="#CC3333">MP1 bets t120</font>, <font color="#CC3333">CO raises to t600</font>, Hero folds, MP1 folds.

Final Pot: t1125

Results in white below: <font color="#FFFFFF">
No showdown. CO wins t1125. </font>