Dwindling chip stack in 200NL 5/2 blinds......

[sp1ke36]

Sorry in advance if this post doesn't belong here.

I've been playing in this game for about six months. I'd say I'm breaking even.

The problem I'm having is that when I have a big stack usually I'm walking from the table short from what I was up.

ex: Last night in the first hour of play I was up about 400 plus my 200 buy-in. I left up 150.

This happens quite a bit. I can't seem to make a big stack grow. Usually only happens if I suck-out on someone or get lucky that someone calls a big hand and it holds up.

I've seen players sit at these games for long sessions and walk away with 2000 to 5000. I just can't seem to swing it. The most I've walked w/is 1200.(mostly luck not skill)

Could it be that:
-The seat charge is pretty steep $7/hr
-I'm not defending my blinds.
-I'm playing too tight when big stacked.
-I'm playing too loose when big stacked.
-I always limp on the button w/limpers before me, should I be raising w/any two.
-I will call a reasonable raise in position w/any two.
-I limp too much out of position.

Also, Let me know your feelings on limping in cash game as I think this could be a major leak for me.