Resistance of both coils is 21 Ohms, drops to around 13 as rotor is manually rotated.
My concern is that just connecting the 5v out from the Arduino to the motor voltage pin referenced in Igoe's notes on the L293D might be drawing too much current to handle. I have no real idea whether this is likely to be a problem with such small motors.
The steppers will still work, albeit with lower torque, without the 5v connected at all, running the L293 at 3.3v is enough for the motor to function. They seem to skitter about a bit more, am I right in thinking that the higher the voltage used in the stepper (to a safe limit) the more controlled the steps will be?