make sure the hinge is not broken. when they start cracking, the lid gets all bend out of shape because the hinge is flexing along the crack.
also, make sure the 2 rubber stops are the correct height and don't interfere with the lid. adjust them by turning if needed.
oh, and check the length of the hinge for the lock. it's also adjusteable and might be too long right now, causing the lid to stay too high.
lastly, the lid itself might just be bend. you can bend them back fairly easy by hand ...
Andy