Brandon has the MM 522 pump & we use the 6mm quicksets. Lately we have been noticing that if we don't put the cap on while he takes a bath (sometimes 1/2 hour long) something turns in the site, and we can't get it connected again. Does anyone else have this problem? Are we doing something wrong? We now have to do a site change tonight after just changing it yesterday before school. ARGGGGG!