The ALS_COMM and ALS_DIFF FIND_IR algorithms have not been working over the last few days, but they have been taking a lot of time to fail.

This evening we rewrote them both.  ALS_DIFF has a nice algorithm which tries the known good locations quickly, and if that doesn't work it searches around those locations.  Unfortunately, the search part has only been tested a few times, because the initial quick check of known locations usually works.

For ALS_COMM, we didn't bother with a search feature.  The known good locations are checked, and if that fails (which is rare) it asks for help from the user.  It would be good to better test the search functionality of ALS_DIFF, and then make ALS_COMM have something similar just to deal with the rare cases in which the known locations fail.