Checking out the link from LK, I read the following:
The Rapid Start lamp operates on the principle of utilizing a starting voltage which is insufficient to start the lamps while the cathodes are cold but is sufficient to start the lamps when the cathodes are properly heated. This voltage range between starting cold and starting hot is a very narrow band of voltage which must be closely controlled by the ballast in order to prevent either failure of the lamps to start or instant starting of the lamps with cold cathodes which is detrimental to the lamps. In order to stay within this range of voltage, it is necessary to excite the gas within the lamps by means of an external voltage applied between the lamp and the reflector or channel (the starting aid).
In order to act effectively, the fixture must be connected to ground
and the white lead of ballast connected to ground lead (neutral) of the power line.
Thus it is stated on the label of Rapid Start ballasts "Mount lamps within ½ inch (3/4 inch or 1 inch) of grounded metal reflector."
Fluorescent fixtures are designed to provide the proper lamp-to-reflector distance.
So, I gather from this that your fluorescent luminaires may have been engineered to not always work unless there is a grounded strip or reflector nearby (1/2 to 1 inch).
It does matter if some luminaires are grounded, and doesn't matter for others that are not engineered to such tight voltages. Who woulda thunk it?????
