Newbie ignorance? (probably low content)

[usmhot]

Comeback thread made me think of this.
Playing Party SNG 5+1
I'm finding recently that I far prefer to find myself short-stacked coming up to the bubble, than have a couple of big wins in the early rounds.
Normally, if I'm short-stacked in the later rounds its because I've had nothing to play with baring the ocassional mid-pair or AQ or something like that which doesn't improve on the flop and I fold to strength.
But, at the bubble, I find it easier to play from short-stack - stealing lots with these same hands (and worse).

It seems that if I get a couple of monsters in the early rounds and take chip lead I somehow fritter it away and end-up getting beat on coin-toss type all-in calls.

Obviously I still want to maximise the early monsters, but is this a newbie phenomenon? Am I just, subconsciously loosening up too much if I do well early on? Or, in other words is this a well-known leak?