is it normal for the slimline 5lnb to shake a bit with winds of 15-20 mph? had it installed yesterday. my neighbor's doesnt shake at all. his has one more spot where it is secured. the installer was suppose to do it just like his but by the time he left after a 5hr install it was dark and i couldnt see exactly how he did it. perhaps i need a service call to have the dish secured better?