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. Source Four reflectors will flake if the reflector has been cleaned with an abrasive cleaning material such as bleach or Ajax. This will damage the reflector and cause it to flake when heat, such as an activated lamp, is applied.