I coded while raiding, so couldn't spam my chat with print messages last night. That's where I found out, what was wrong.
The problem I have is that somehow in raid, it shows me *all* debuffs and ignores my filters, when I have line 31-32 in my filter. But when I delete them I don't have NPC buffs/debuffs on my target inside normal 5-man dungeons (like the alchemists in UBRS).
Oh, also I added in the OP that I also use this filter on my target buffs, not only debuffs:
Lua Code:
self.Buffs.CustomFilter = lib.AurasCustomFilter.target
self.Debuffs.CustomFilter = lib.AurasCustomFilter.target