getting bullied, call here? push preflop?

big stack has gone all in everytime i raise, reduced my stack by $1200 already (2 $600 raises I folded)

Hold'em No Limit - Level VI (100/200)
Seat #8 is the button
Seat 3: lrlslo (1050 in chips)
Seat 7: rushtrio (1225 in chips)
Seat 8: Hero(1810 in chips)
Seat 9: FrozeLast (9415 in chips)
FrozeLast: posts small blind 100
lrlslo: posts big blind 200
*** HOLE CARDS ***
Dealt to Hero[7c Ad]
rushtrio: folds
Hero: raises 200 to 400
FrozeLast: raises 9015 to 9415 and is all-in

Hero? Should I have pushed preflop? I'm really pissed that he's been able to bully me twice already at this point.

Hand 2:

Big Blind is t200 (4 handed) converter

SB (t1450)
BB (t1650)
Hero (t1110)
Button (t9290)

Preflop: Hero is UTG with 2[img]/images/graemlins/heart.gif[/img], 2[img]/images/graemlins/club.gif[/img].

Hero??

Hand 3:

PokerStars No-Limit Hold'em Tourney, Big Blind is t200 (3 handed) converter

Button (t2325)
Hero (t3245)
BB (t7930)

Preflop: Hero is SB with A[img]/images/graemlins/spade.gif[/img], 4[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">1 fold</font>, <font color="#CC3333">

Hero??