As far back as ColdFusion 6 PreserveSingleQuotes hasn’t worked with array style parameters.

This was even submitted as ColdFusion Bug number 53977 on the CF6 docs, a few years later and we still have no joy for ColdFusion 8

Structures will work but only when you access the value by dot notation, not using array style:

This was annoying today when I wanted to loop over an array of “WHERE” clause arguments passed into a function. I needed to either change the calling code to pass a structure instead, or set the arguments array element to a local variable inside each loop iteration to use inside the preserveSingleQuotes

Hopefully Adobe will fix this small bug in the next (Centaur) release!