Bulb age/PAR reduction... and you heard it was just spectrum shift?

[grouper therapy]

This is the info I found on a website from Sanjay
One problem with the electronic ballasts is that they often have to be tuned to the specific bulb or classes of lamps. This may be a problem if you want to change from say a US made lamp to a German or Japanese lamp, since it requires sending the ballast back to the manufacturer for re-tuning.
Just did not know about the icecap.