I absolutely agree that you should buy in for the full amount. Buying in for less puts you at a disadvantage because you are not able to extract the max value form a good hand. In addition, once you have more than the max buy-in for a table people seem to respect you a little more. I've found that when my stack is 3-4x the max I get a LOT more people folding which helps me steal more blinds and bluff. It sounds like you may be stretching to play at higher stakes than your roll can handle. If this is the case, drop to a low limit table and buy in for the max. I know that it seems hards to believe, but "luck" is a illusion. Streaks or Runs only exist in the past. Make sure to consider position, number of outs, pot odds
, expected value
, etc and play smart. If they are playing recklessly they will suck out on you sometimes but you WILL come out ahead in the long run if you play smart.