overpair JJ facing heavy flop action

[gumpzilla]

Stars $11, 1 rebuy, 1 addon. I took my rebuy immediately. Table has been pretty donkish, as a whole. BB in this hand has been playing a fair number of hands and firing pot sized bets on the flop pretty often, so I don't think this is representative of that much strength. MP (oldmanricky) made his main impression on me by raising UTG+1 with AJ for 4xBB and then calling a ~100BB push.

PokerStars Game #2645371343: Tournament #12672552, Hold'em No Limit - Level IV (50/100) - 2005/09/23 - 21:22:04 (ET)
Table '12672552 101' Seat #2 is the button
Seat 1: Subby8000 (4640 in chips)
Seat 2: MtlBndr (3300 in chips)
Seat 3: gumpzilla (3240 in chips)
Seat 4: nanc73 (4935 in chips)
Seat 5: TrueJacks (4390 in chips)
Seat 6: Red Lion 70 (1080 in chips)
Seat 7: Jayshore (1875 in chips)
Seat 8: 2005XKR (11980 in chips)
Seat 9: oldmanricky (3390 in chips)
gumpzilla: posts small blind 50
nanc73: posts big blind 100
*** HOLE CARDS ***
Dealt to gumpzilla [Jd Jc]
TrueJacks: calls 100
Red Lion 70: folds
Jayshore: folds
2005XKR: folds
oldmanricky: calls 100
Subby8000: folds
MtlBndr: calls 100
gumpzilla: calls 50
nanc73: checks
*** FLOP *** [9s 4d Tc]
gumpzilla: checks
nanc73: bets 500
TrueJacks: folds
oldmanricky: raises 1000 to 1500
MtlBndr: folds
gumpzilla: ???