I just experienced the oddest quirk: I logged into my single player map ... and noticed that all my researchpoints from Thaumcraft are gone. I am back to the 6 primals when I open my research table, though without even any points for any besides 1 ordo and 1 terra... annoyingly enough, all items still count as scanned, so I can't even get back all the aspects I lost. The research I made also stayed where it was, so I only, for some reason, lost all my research points. Some googling showed me that this could happen after updating Thaumcraft versions, but I did no such thing.
Edit: Used /thaumcraft aspect [playername] [aspect] [#] to get myself some primals again ... I'll just combine them again for now.