I had an Ergal break around a ferrule, popped out a section about the size of a dime. Inspection showed hairline cracks around other ferrules. My solution was to have the rear wheel rebuilt with a 36 hole Fiamme red label. (The Ergal on front seems ok) I really haven't rode it much since so can't say I cured the problem, but it seemed like the way to go. The wheelbuilder advised cautious riding, in that the rims are light and I are not.
Pete Geurds
Douglassville, Pa