I've noticed that since 1.08, my characters have been resisting their own buffs such as those you get from eating fairywodger/night cap and thaumatheurgic tap--essentially, anything that heals or restores mana over time has a pretty good chance to be resisted. This didn't use to happen in 1.0.6, did something change? I don't think this is intentional, is it?
I've noticed the same thing. It was happening in 1.07, too. I'm guessing that DoTs were hooked up to the magic resist stat and HoTs shared enough of the same code that they got dragged in too. It makes Fleshsmithing a real drag, which is too bad because it's finally been buffed to a point where it's worth taking.
Well, I think most of the buffs were already in as of 1.07. Or maybe even a patch earlier; I'm not totally sure. But Knit Flesh didn't used to scale with magic power, and Corpus Burst used to deal less damage and not leave the poison cloud. And the new damage cloud mechanics in 1.08 are a massive buff to Miasmic Putrefaction (and the redone Corpus Burst too).
Maybe this was obvious, but for the record: I checked the XML and Knit Tissue and similar HoT effects are marked as effect type="dot". So the game definitely can't currently distinguish between damage and healing effects; HoTs are just DoTs with negative damage values. So whenever DoTs became resistable, HoTs got it too.
The same is true for Thaumaturgic Tap in Leylines. I keep resisting it, which makes things REALLY suck at monster zoos. I actually had a really good shield with Magic Resist, and I ended up sending it to the museum for an inferior Orb that had no magic resist