Do previous hands influence how you play a particular hand?

[Rvr_B_Good]

(my first post so go easy guys...)

MTT
1st round, 3rd hand
Blinds 25-50
I'm one to the rigt of the button and everyone folds to me I call 50 with A [img]/images/graemlins/club.gif[/img] Q [img]/images/graemlins/spade.gif[/img]
button folds SB calls BB checks

Flop A [img]/images/graemlins/heart.gif[/img] 9 [img]/images/graemlins/diamond.gif[/img] 6 [img]/images/graemlins/diamond.gif[/img]

SB bets 150
BB folds
I raise to 300
SB quickly throws in 750
(now i had just had 99 previous hand and hand before that another player had 44-so my thinking was he probably didn't have a set and he would not have just called with AK)
I push, he calls
turns over A [img]/images/graemlins/spade.gif[/img] 9 [img]/images/graemlins/spade.gif[/img]
turn and river were blanks.

other than not thinking about two pair, was it right to assume he wouldn't have a set or AK? and would it have been better to raise to 150? 200? on the opening bet?
(don't really know this player's style)