You can unbolt the covers from the table and slide them towards the outside. You can unbolt the ends and remove them completely if you need to straighten out a dent or something. I just spray them down with WD-40 once in a while and they don't give me problems. The ones that do are the Z covers. The grooves they slide in get packed up with 5hit and they pop apart.
Also, the X covers are supposed to make a pop sound. They bang into each segment as they move. Sometimes one sticks a little and it's louder than the rest, but it's normal for them to be a little noisy.
Apparently I don't know anything, so please verify my suggestions with my wife.