Hi Dave,
Yes, I've heard of it. I also have a 2007 CD-25. We are on our third fresh water pump. The first one failed at a bit over a year. The second one (same model) didn't make it that long, and that was after I moved it up in the bilge so it wouldn't sit in the water. The third one is a pump designed for marine use... when I looked up the pump #, I found that the original and replacement pumps didn't have that designation.
Our first pump failure started with the symptoms you describe, and then worked intermittently for a couple months. I'd recommend you move the pump off the bilge bottom and replace it with one designed for marine use.
Best wishes,
Jim B.