5/10 set of 4s up against possible flush.

[diconoclastx]

Is this an easy fold? Should I have blocked the turn?
Villain is 34/10/2 after many hands.

***** Hand History for Game 2508062106 *****
$1000 NL Texas Hold'em - Tuesday, August 09, 22:17:41 EDT 2005
Table Table 48711 (6 max) (Real Money)
Seat 2 is the button
Total number of players : 5
Seat 4: HERO ( $1681.75 )
Seat 5: smalltalkdan ( $1713 )
Seat 1: ACE435 ( $1731 )
Seat 2: tna1042 ( $557 )
Seat 6: woodear ( $866 )
HERO posts small blind [$5].
smalltalkdan posts big blind [$10].
** Dealing down cards **
Dealt to HERO [ 4c 4s ]
woodear folds.
ACE435 folds.
tna1042 calls [$10].
HERO calls [$5].
smalltalkdan checks.
** Dealing Flop ** [ 9d, 5s, 4d ]
HERO bets [$30].
smalltalkdan raises [$110].
tna1042 folds.
HERO raises [$270].
smalltalkdan calls [$190].
** Dealing Turn ** [ 3d ]
HERO checks.
smalltalkdan bets [$650].
HERO ?