Bet the nuts when you got it...

Speaking of NOT betting the nuts; this guy is overbetting the nuts. This was a hand I played on Monday night. MP2 was 8/4/1.0 @ 49 hands:

Full Tilt No-Limit Hold'em, $0.10 BB (9 handed) - Full-Tilt Converter Tool from http://www.flopturnriver.com

UTG+1 ($5.25)
MP1 ($5.64)
MP2 ($6.72)
MP3 ($20.45)
CO ($10.06)
Button ($0.79)
Hero (SB) ($6.98)
BB ($4.52)
UTG ($11.61)

Preflop: Hero is SB with 9d, 7d
3 folds, MP2 bets $0.20, 3 folds, Hero calls $0.15, 1 fold
I call here, out of position, against the tighty with the intent of folding a missed flop.

Flop: ($0.50) Kd, 9h, 6s (2 players)
Hero checks, MP2 checks
I catch a piece and a backdoor. I check / he checks behind.

Turn: ($0.50) 3d (2 players)
Hero bets $0.30, MP2 calls $0.30
With a pair and the flush draw, this was probably a bad bet out, given how quiet he has been to date in the hand. However, I figured I'd take a stab. If nothing else, I have outs to the river.
River: ($1.10) 10d (2 players)
Hero bets $1.25, MP2 raises to $6.22 (All-In), Hero calls $4.97
Awesome! The beloved backdoor flush! How can this be beat?!?!??!
Total pot: $13.54 | Rake: $0.90

Results:
Hero had 9d, 7d (flush, King high).
MP2 had Qd, Ad (flush, Ace high).
Outcome: MP2 won $12.64

Are you getting away from the backdoored flush? His checked flop / called turn says he either has air or a monster. I am not putting a nit on smoothing the turn bet with nothing. However, the river all-in clearly delineates he has a set of some sort or a straight. I'm not putting him on a flush AT ALL; nor he me, I guess.