Anyone playing with Beta 13 have a little time to spare for some field study? Just take a dioptra and wander about the world a bit by various methods of differing speeds, plunking the dioptra down here and there and looking for swathes of chunks with no aura. (Not just low aura, zero aura.) Trying to reproduce/isolate a problem and determine how common it is, and gather data to figure out whether specific combinations of mods trigger it.
It wasn't a mod conflict. It was a Forge configuration issue.
Forge has the following optional feature, which you'll find in config/forgeChunkLoading.cfg:
# Unloaded chunks can first be kept in a dormant cache for quicker
# loading times. Specify the size (in chunks) of that cache here
DO NOT ENABLE THIS CACHE. It sounds like it would be useful, but it totally breaks Thaumcraft aura generation.