Fluorescent light that keeps flickering

It sounds like you have indeed bought fluorescent bulbs. manufacturers are encouraged to replace the incandescent bulbs with more energy saving fluorescent bulbs. They are made to look like standard bulbs so you need to look at the package carefully to see the difference. The Nu Tone and other special bulbs may still be available in the old filament style for a while but you may have to look harder or ask if they are still available. The amount of flicker often reflects the quality of the bulb. It will sometimes decrease over time.

If your shop is in your garage, and it is cold outside, the two-pin fluorescent tubes don't work very well. Garage lighting (fluorescent) should be the HO (high output) type. It operates on the same voltage. The tubes are not interchangeable. You need a HO fixture. If your shop is inside your house, then flickering tubes (assuming that you tried changing them out with new ones) indicate a bad ballast inside the fixture. You can either change out the ballast, or for almost the same price, replace the fixture.

I'm sure they made it that way for a reason. Unless you know the specifications will match, don't try to jerry-rig it to fit.

disconnect the power and try to pry the prong in the socket of the light outwords,check the connection in the unit itself

The lamps are both using 40 watts of energy, but the fluorescent lamp gives more lumens (visible light measurement) than the incandescent.
Fluorescent gives at least 5000 lumens for 100 watts.
Incandescent gives 1750 lumens for 100 watts.
You can see that if you had a 100 watt incandescent, it would be 1750 and you would only need 35 watts of flourescent.
Gary

-Replace the compact florescent bulbs with regular incandescent bulbs and see if problem continues.
-Lighting controls are made for different kinds of bulbs.
-Your package should say what the watt rating and type of bulb.

According to the PR180 manual:
-I am looking at the Leviton PR180 occupancy sensor manual, and the PR180 sell-sheet, and these documents say for incandescent and fluorescent (rapid-start magnetic ballast only).
-Compact fluorescent are supposed to have a magnetic ballast.
-The manual does not specifically say it works with 'compact fluorescent'
-The manual does not say there is a minimum amount of wattage either. Some controls will not work correctly if the overall wattage is low. Your overall wattage is 39watts.

Read the product package (if this is a new installation and you have the package)
Try the incandescent bulbs.
If the PR180 is not your product, add a comment with product number and I'll look for information

If the saver bulbs are of Fluorescent lamps type, they can not go to 0 even to 30% (depending on mains voltage: for 240V mains the range is bigger), because they need minimal voltage of about 80-100 V in order to keep the electrical arc. They vary the light level, but if by a normal dimmer give them less than about 80-100 V (max value), they will go out.
You have about 80% iconomy(compared to normal incadescent lamps) at rated voltage and it can be rased to 90 - 92% at minimum light, but not more.

You should use a special diimer if you wish to use the whole range for dimming.

thermostat on the fixture is busted

Solids state fan controls don't work correctly with fluorescent bulbs. If you check the tail end of you remote's instructions it will say something like "Max light watts: 300 (incandescent only). So replace your energy saver bulbs with 60 watt "regular" bulbs to solve your problem.

Inside a fluorescent light, electricity is delivered to a ballast, which sends a spark through the mercury-vapor-filled tube (or bulb), creating light by activating phosphors that coat the inside of the tube. If any of the components are faulty, the light won't work right. Once you pinpoint the problem, most fixes are very easy. Remember to turn off the power first! Old bulbs blink off and on just before they die; repairs are often simply a matter of replacing the tube or bulb. This problem may also be occurring because of poor contact between the pins at the ends of a tube and the tube holders. If the pins are bent, use needle-nose pliers to straighten them. Clean up the pins and socket contacts with fine sandpaper, and brush away residue. Though gray bands at the ends of tube are normal, black bands indicate that the tube needs to be replaced. If only one end is dark, turn the bulb end-for-end. If the tube is new and these fixes don't work, you may have to replace the starter or ballast. Some fixtures ("A-rated") are quieter than others are, but most fluorescent lights have a slight hum. If the sound seems too loud-- or if you can smell electrical burning-- shut off the power. The ballast is probably either the wrong type, improperly installed, or defective. Replace it or call an electrician. Brand new tubes tend to flicker, as do bulbs that are cold. If an old tube still flickers after it has had a chance to warm up (or after you've warmed up the room), rotate it a couple of times in the tube holders. Try cleaning the tube's end pins. If it still doesn't work, replace it. If only the ends of the tube glow, either the starter or the ballast is defective. Replace the starter, then the ballast.