Back at the beginning of the miniDV revolution, many people found that if they used tapes made by different manufacturers in their camera that the heads would eventually gum up and require some serious cleaning. The cause was determined to be that Sony tapes used a lubricant type that, though fine by itself, would react with the lubricant used on tapes by other manufacturers and gum up the works. To avoid this problem, people would only use one brand of tape in their camcorder.
I've heard that the manufacturers have all made their lubricants compatible now, and that it is ok for a camcorder to not be a tape monogamist. I can't say for certain that this is true, but I can say that I have used Sony, TDK, and Panasonic miniDV tapes interchangeably over the past couple of years in my 2 miniDV camcorders and have not had a single problem.