HMM well I haven't noticed the magicka costs going really low again but I did have a strange issue. I had been wandering around using a powerful light spell costing 140 magicka, my illusion skill being around 95-98 I'd occasionally get a disease, or see a quick spell effect show up when casting the light spell. Then I summoned a lich (340 magicka, 74 Conjuration skill)...
Using default settings you had 125 skill vs 340 magicka cost, so a nasty penalty is no surprise. A huge difference at -26 skill isn't really how I intended the mod to work, but it's mostly a problem with how Oblivion handles magic skill progression. Basically, spell costs don't scale evenly, and there ends up being a huge magicka cost drop as you approach mastery skill. Race Balancing Project fixes this issue by evening out the spell cost progression. There may also be some standalone mods that fix the issue.
All of my stats hit zero and I was knocked out and over encumbered on the ground. After eating a few restore willpower, strength,fatigue, etc. potions I was able to http://img.photobucket.com/albums/v189/phoenix7/Oblivion/statslow.jpg. I thought, "Damn! maybe it was the diseases" but, nope they only account for a http://img.photobucket.com/albums/v189/phoenix7/Oblivion/statsaftercure.jpg of the damaged stats. After using a restore 10 every attribute spell a couple times things started to look better, but my intelligence was capping out at 157 even without any fortify items (except for Julianos' blessing which only gives 5)... I did end up fixing it by using the unofficial patch's "fix attributes" feature(The UOP fixed other attributes like strength by like 8 and speed by 10, but Intelligence was the most obvious screwy stat), but I figured I'd report it if something went screwy with this mod.
What you encountered was a particularly nasty penalty. I don't think that sort of attribute damage is much fun though, so I've changed things for the new version.
By the way a bit nit picky but, why do all of the non disease effects have no names? I mean most of the time when you see "Damage magicka" "magnitude 50" you don't need a witty name to explain that to you, but... it's still nice to have
. There is a script effect named "unknown" that shows up every now and again though. Also the the "school advancements" still say the vanilla thing: "You can now cast Apprentice/journeyman/expert/master spells!"
I guess I never noticed the lack of names. That has been fixed
Update v1.05:Removed an unpleasant penalty.
Added new customization options: set the mastery multiplier for each school of magic individually.
Cleared up some confusing wording.
Penalty effects now show the name of the spell that caused them.