When I white balance an EX1 in my studio, which is lighted with daylight balanced flos, the camera indicates the color temp is 5300K. Does it matter, as long as I white balance before shooting? Is this common?

Unless your room is painted white, with all white fittings and floors, then the light colour is a product of the light source, plus reflected light. You're very close anyway, so not worth worrying about. If the camera can balance to it, it's fine - and 300 degrees at the blue end is not much of a shift anyway.

Thanks Paul. The reflected light is likely the reason for the difference. Since 300 doesn't mean much, I won't worry about.

I have checked many different flo lights that claim a particular color balance with a calibrated color temp meter, and many of them are off by 200 - 300 degrees. Some are off as much as 400 degrees. As Paul mentioned, do a manual white balance and you should be just fine.

All the Best!