Yes and no! Electronic timers, photocells, or lighted switches may not completely block the flow of electricity when turned off. This is commonly referred to as leak-through or pass-through voltage. Even though the amount of voltage is low, it can be detected by a compact fluorescent light bulb (CFL). As a result, the circuit board in the CFL may try to start.
Since there isn't sufficient power to start, the CFL cycles of an on in a strobe light manner - eventually burning out the CFL circuit board components resulting in early bulb failure. With this in mind, can you blame CFL manufactures for putting "don't use with" disclaimers on the packaging?
However, devices that meet the following UL standard can be used with CFL.
UL20 Sec. 7.6.15
7.6.15 Switches that are marked OFF shall completely disconnect all ungrounded conductors in the circuit when in the OFF (open) position. Switches that do not disconnect all ungrounded conductors, including switches that incorporate in-line components, such as neon indicators, that pass current through the load when the switch is in the open position, shall not be marked OFF. (Some timers, photocells and lighted switches still receive the leak-through voltage in the OFF position, which is why the UL standard must be met for use with CFLs.)
Found a timer, photocell, or motion sensor that that meets the UL requirements? Get some CFL bulbs to go with it here.