Nater, since I don't know what you've done, I can't tell you what you've done wrong, if anything. I need your Project Folder and, if the stock airport is not a good representation of your current airport, the airport .bgl you are using.
First of all, a new version of AFLT is almost ready for release. So I suggest you hold off upgrading for a day or so and use the new release.
However, the new release won't do anything about your current issue since it doesn't make any changes to reverse mipmapped effects. You haven't indicated whether or not the reverse mip-maps were working properly before. Have you tried changing the size of the effect or the effect size multiplied? AFLT ships with default values that are reasonable, but may not provide good results in every case. Have you tried sung other light sources?