Yes! you're totally correct! thanks a lot man :D
Here's the line
FlxG.camera.setBounds(0, 0, tileMapWidth, tileMapHeight, true);
where tileMapWidth and tileMapHeight are in pixels (tilesize in pixel * number of tiles).
Yes! That's the way, sorry for not posting the code before but i wasn't at my computer, nice to know you got it right!