NL100, common spot with NFD

[tubasteve]

Full Tilt Poker - No Limit Hold'em Cash Game - $0.50/$1 Blinds - 5 Players - (LegoPoker Hand History Converter)

SB: $223.70
BB: $102.35
UTG: $90.05
CO: $99.50
Hero (BTN): $108.20

Reads: <font color="blue">new to the table, and on a new computer, so no reads [img]/images/graemlins/frown.gif[/img]</font>

Preflop: Hero is dealt 4[img]/images/graemlins/diamond.gif[/img] A[img]/images/graemlins/diamond.gif[/img] (5 Players)
<font color="red">UTG raises to $4.00</font>, CO calls $4.00, Hero calls $4.00, 2 folds

Flop: ($13.50) Q[img]/images/graemlins/diamond.gif[/img] 6[img]/images/graemlins/diamond.gif[/img] T[img]/images/graemlins/heart.gif[/img] (3 Players)
<font color="red">UTG bets $12.00</font>, CO calls $12.00, Hero...

calls or raises, and why? I know it's hard to say without a read, but whats standard here?