Sometimes, on rare occasions, the suction cups can become unsealed in the shipping process, or after years of use. Because of the design, the screws have to be tight in order for the suction cups to be sealed, and therefore hold suction. 

If you ever feel that suction power is not what it should be, do this:

Take a Phillips head screwdriver and slightly tighten the screws that go through the suction cups into the product (all 10 of them). 

*Be careful not to tighten them too tight. If you tighten them too tight, it can cause a small bump to protrude through the other side. This does not compromise the integrity of the product, but it may effect the way the product looks in apprearance.