Has anyone had any problems with there sand joints not setting correctly. We have done alot of jobs and it seems that a month or so later we get a call back and the polymetric sand we use for the joints (gator dust, poly sand, or a similar product) is one either is completely soft or it pulls out as one entire strip, that is fairly soft as well. Anyone else having this problem. The joint size is either 1/2" or more. Any thoughts would be appreciated.