Josh,
Unfortunately it's not unusual. It is, however, very hard on the A/C. You really want the unit to run for several minutes and be off for several minutes, at a minimum.
It is caused by the discharge air from the A/C blowing on the thermostat tricking it into thinking that the room has cooled down. It shuts off and immediately "feels" that the room is too warm and re-starts. The first thing to do is re-direct the vents away from the thermostat as much as you can.
As you know, there is a ton of air blowing around in a pretty small room. The problem will improve slightly when the temperatures outside and sun heat loads go up.
Depending on if your thermostat has this setting, you should make sure the differential is set to a higher number. This is the difference between the temperature where the A/C comes on (Setpoint) and shuts off (setpoint - Differential). Some thermostats also incorporate a re-cycle timer, like a minimum off time, but this is pretty rare.
I have replaced mine with Hunter Digital thermostats and run the bedroom with at least a 2 degree differential, but still have to be mindful of vent opening and direction. It also helps when I keep the bathroom pass through door open to the bedroom.