We've had our Dolphin s300i for a little over 3 years (this is its 4th summer), and a few weeks ago it began having issues. It would start moving when we turned it on, would go forward and back a few times, then stop. Tried some troubleshooting suggestions from Maytronics, which didn't fix it, then took it to an authorized service shop. They didn't see anything wrong with it after taking it apart, and when they put it back together it ran a full cycle just fine. We brought it home and it ran 2 full cycles over the weekend. Now it is having the same issue as before (stops after less than a minute). Has anyone else experienced this? I'm hesitant to bring it back to the service shop since they "fixed" it before and it didn't last.