We puchased our frig. in 1995. It's been a great frig. but about a year ago we started having trouble with the ice maker. We purchased a new one and that worked for about 6 mos. then stopped. We had a repairman come and look at it and he said that the tube that brings in the water was all frozen. He removed the frozen ice and the maker started working again. However, that tube is frozen again. What can I do too stop this? Is there another problem I should be lookining at. The frig. works fine otherwise.