It isn't the air current that's the problem, it's what is being carried on the air current. Dust. Most of the lower grade detectors can't tell the difference between a particle of dust and a particle of smoke. When you switched direction on your ceiling fan, did you notice any dust on the fan blades? You could try thoroughly cleaning the fan blades and fan itself and give that a go. Or, you could just return the fan to it's original directional setting (or both).
Photo electric sensors are better than the older ion detectors. But the more basic single optic detector units are still quite prone to false readings. I'm not even sure if dual optical sensor detectors are available for stand alone residential use, but I am a commercial fire alarm tech, and that is the type of detector we install in commercial buildings. The dual detector, twin mirror units are much more reliable. You can still get false alarms, and a dirty commercial setting would still be a problem, but the improvement is significant. Also in a commercial system, you can program different sensitivity settings into individual detectors that may be in different environments.
Also, there is a new standard coming out for smoke detectors, which is even tighter on allowable false readings parameters. We have several commercial detector models that will become obsolete when the new UL standard "hits the streets".