So, I have this weird issue w/ my Drinkwell fountain. Suds that look like soap suds keep appearing after the fountain runs for a while (but not right when you turn it on.) I've changed the filter, washed the whole thing out by hand and through the dishwasher. I thought the suds may be coming from the motor, but i've been rinsing that out a lot too. Has anyone had this happen? Any suggestions how to fix this?