As stated on the fixture, it has been tested to use UP TO a 75 watt lamp and still meet safety requirements at the factory.

CFLs can be misleading, as most state "equals a 75 watt lamp" but what it equals exactly is the question. You want to find a lamp that has a high CRI(color rendering index) above 81 if possible, as well as a high lumen output.

Yes, the fixture is rated to hold a light runing at 75W. Your CFL is only running at 19W, the "equivalent" rating is trying to tell consumers that this 19W bulb puts out the same light as an incandencent 75W bulb, not that it burns that much energy. You can easily step up to the 23w CFLs if you want more light ourput. I persoannly have tried several CFLs and can't find one we find acceptable from a color quality standpoint. Maybe when LED becomes more affordable.

Watts is what creates the heat. With a 75 watt limit on the fixture, you're right-on that a 19 watt CFL can be increased to a 25 watt CFL and still run much cooler that a 75 watt bulb.

Recessed incandescent light fixtures are limited in wattage and lamp type (PAR, R, ER, BR, etc.) in order to avoid exceeding the heat limit of the fixture and possibly tripping the thermal limit protection built into it (as tested for safety by UL, etc.)

A compact fluorescent lamp with an integral ballast will also create quite a bit of heat in a recessed fixture but whether it will exceed the safe limit of the fixture is impossible to tell since it wasn't tested with that type of lamp.

As a practical matter you can try the CFL lamp and see if it trips the thermal limit protection in the fixture. If the lamp generates too much heat it should turn itself off and then restart when the lamp cools.

If you want a UL tested long lasting energy efficient recessed light fixture consider one designed for a CFL lamp with the ballast in the fixture housing.

Been away from my computer since I posted question. Macy, what do you mean when you said, "If you want a UL tested long lasting energy efficient recessed light fixture consider one designed for a CFL lamp with the ballast in the fixture housing"? For my recessed light fixtures which stated no more than 75 watts, I used a spotlight CFL with the fluorescent tubing encased within the bulb. I believe it was equiv. to a 100 watt bulb. Is this what you are talking about? So far, no recessed light bulb has gone out.

The ratings IMHO merely reflect what a normal incandescent light fixture max wattage is due to the heat these lights generate.