Shitty hands from sb.

I do this every time with A7-A2 and K10-K8o, QJ-Q10o,66-22 and 65s vs players who raise sub 5%. I play less hands the more they raise obviously. So is this just bad or is it justified. For the record I raise with A9,A7s,KJ,88,K10s,QJs. What about raising with 55 and 109s? Or maybe any A.. Im somewhat confused. Also how much does this depend on the BB.

Party Poker 1.00/2.00 Hold'em <font color="#0000FF">(6 handed)</font> link

Preflop: Hero is SB with 5[img]/images/graemlins/diamond.gif[/img], A[img]/images/graemlins/club.gif[/img].
<font color="#666666">2 folds</font>, CO calls, <font color="#666666">1 folds</font>, Hero completes, BB checks.