How much are you watering? They could be fungus gnats or white flys. Do you get white spots on your leaves from an insect biting them? That could be white flys. If your keeping you soil too moist it could also be fungus gnats. Their young eat decomposing matter in the soil (somtimes a little roots but it won't hurt an established plant). They tend to look like fruit flies. If your watering too much it can make the leaves drop, the insecticidal soap usually won't harm the plant as it is very mild. Try using a water meter from Home Depot or Lowes (they are usually pretty cheap and I've found them VERY helpful). I haven't herd of the cigarette treatment but I have herd wattering with a little vinegar in the water can help. The link might help you out, although it doesn't cover the gnats (they are a common problem with houseplants though). Also visit http://www.plumeria101.com/problems.html for pictures of some common problems.

Amanda

Here is a link that might be useful: Plumeria Pests & Diseases - PSA

For me, I find most of the potting soil right from the bag to hold too much water - especially now since all of them seem to be including ingredients that hold water (I guess it's the new fad to call themselves "moisture control")

I use organic soil (a personal preference) and add quite a bit of perlite to it for drainage. Pure soil = fungus gnats for me since lots of my tropical plants like to be kept damp. This way I can water them as much as they like but the tiny air pockets created by the perlite prevents fungus from forming so the fungus gnats do not lay their eggs in it.

I do try to keep my soil quite moist for the most part, as it can get pretty dry up where I live. I'll try to let the soil dry a little more than I usually do in between waterings and see if that will help. I'll also try the vinegar thing, do you know how much vinegar to water it should be?
Thanks a lot for all the help so far!

Sounds like fungus gnats to me. another organic approach involves placing dish with red wine on the soil to attract the adults and cross cut potatos cut side down to the soil to attract the larvae.

I was off on that, the gnats are attracted to vinegar so your supposed to put it in a jar with a hole in the top or you can put it in a bowel covered with saran wrap with holes poked in it. This will only deal with the adults though and not the larva living in your pots. I've herd the potatos like kms2 suggested are good for getting the larva.
I hope that helps! I just let it get bone dry 2-3 times and they're usually gone. I've never tried anything else.

Here is a link that might be useful: Gnat control