To the OP, here is a possible problem:
After you clean the bearings, how do you dry them? If you dry them with a hair dryer or some other heat source, you might be drying them just a tad too long. If you dry them too long, it will cause the plastic ball retainers to get brittle/weaken. Just another thought. I still think cleaning them with water is a terrible idea. How hard is it to pick up some acetone, 91% rubbing alcohol, or mineral spirits? Also, you never said what you are lubing them with.