My Allin Prelop Results - Statistically Relevant?

[Utah]

Given that I have played 1,000s of hours online and given that I have consistently won over that period, I am far from someone who believes that online sites have inaccurate or faulty shuffles.

However, I switched to pokerstars about 300 sngs ago and I have a return of about 30%, which is low for me. I noticed that I was losing a ton of favorable all-ins. So, I started tracking them.

Over the last 122 preflop allins:

When favorable: 78 times. Lost 38. Win Percentage: 54%
When Unfavorable: 43 times Lost 35. Win Percentage: 19%

Overall, I am 48wins and 73loses even though I was favored 64% of the time.

Is this statistically significant? How big does my sample have to be to indicate a concern?

Thanks