Fixtures that were manufactured between 3/99 through 6/99 have had issues with flaking of the reflective coating on the reflector.
ETC will supply the site with new reflectors, free of charge. However, please get as much information as per the use of the fixtures, when installed, and the average use.
Coating on modern reflectors should not be flaking. If it is, it is most likely due to improper chemicals used in cleaning.