I am having problems with my VDO sumlog. My HR352 is 21 years old so I guess the log is 21 years old. I always remove the log when I leave the boat for more than a day. so it is always popping in and out. It doesn't seem to wake up until we have covered about 4 miles and now it is reading very much under what it should. There appear to be magnets in three of the veins (the thicker ones), so what could be the problem. Furneaux Riddall were less than helopful except to give me a number to call at VDO technical in birmingham only there is no one there and the answermachine tells you it is full. Any ideas anyone. Do logs just wear out ?Duncan