You read this
Low Stakes Sit N Go Tournament Strategy ?
And tried to apply it?
Before you even bother looking at that article you need to look at hand rankings charts and a whole bunch of other stuff too.
Why does the person with A/J or even A/10 call your all-in? Because those are both decent hands. They're not the greatest but they're far from the worst and they're perfectly good drawing hands. Why did they win? Because being good drawing hands they outdrew you. Simple enough and doesn't have anything to do with Full Tilt being a good site or a bad site. Get it?
Also, if all you do is wait for really "good" hands in a cash game, you're in trouble there too. An awesome starting hand can only do one of three things, double(sometimes you get really lucky and 3 or 4 people are along for the ride, but you still have to win) you up quickly, lose, or take the blinds. That's it.
Anyway, don't blame Full Tilt. It's not their fault you play the way you do, and it's not their fault other people play the way they do.