I've got a strange issue with magic.

When I switch my spell to flare, and I cast it, the game will right after automatically switch my spell to <>

Active Mod Files:

00  Oblivion.esm01  Unofficial Oblivion Patch.esp  [Version 3.4.5]02  UOPS Additional Changes.esp03  DLCShiveringIsles.esp04  Unofficial Shivering Isles Patch.esp  [Version 1.5.2]++  USIPS Additional Changes.esp05  ExnemRuneskulls.esp06  OWC - Mannequin.esp07  OWC - Seaworld.esp08  OWC - New Dimension.esp09  Quest Award Leveller.esp0A  SupremeMagicka.esp  [Version 0.90b]0B  SM_ShiveringIsles.esp  [Version 0.90]0C  SM_EnchantStaff.esp  [Version 0.90]++  SM_NoSpellLights.esp  [Version 0.90]++  SM_Scrolls.esp  [Version 0.90]++  SM_SigilStone.esp  [Version 0.90]0D  No psychic guards v1.2.esp0E  Oblivion XP.esp0F  Bashed Patch, 0.esp10  Duke Patricks - Melee Combat NO RECOIL.esp  [Version 5.9]11  Duke Patricks - BASIC Script Effect Silencer NIF REMOVED.esp

If I remember correctly, the switch to the default heal minor wounds spell is a fail-safe of the Oblivion engine. I believe that's why it's often recommended not to ever mess with that particular spell and to be sure to leave it in your spell inventory.

If I had to guess, that flare spell is scripted or has been altered by a script and there's a problem with it specifically.

Are you still in the tutorial? My recollection, although it has been several months, was that SM caused this during the tutorial, but after you left the sewer it stopped and everything was normal.

Very interesting. Thank you.
I don't have many mods, and I thought that the culprit could have been the supreme magicka esp which I edited a bit recently.
But, after removing supreme magicka, I noticed that the bug didn't go away.
I feel like the bug revolves around the fact that I'm using a custom race added by WC: New dimension.

To Turija: the first time I experienced the bug, yes, I was in the tutorial.
But, curious to check if it was a problem related to the fact I was inside the tutorial, I added the mod <> and, after starting a new game, I landed on the anvil dock to see if I had the same problem. And actually, I experienced it once again.

I've got another little issue: sometimes, my character goes in sneaky mode automatically when he is being attacked. Whis is this happening?

And another question: I've installed Darnified UI and moved (via the setting menu) the sneak eye to the center. Is this supposed to happen? I remember that when I played the game there was no need to move the eye to the center, because by default it would always be there. How is it possible that my sneak eye was behind the map bar? XD

I've never used an alternative start mod, so I don't know anything about that or the problem you described with sneaking. The only additional piece of information I have is that when I was in the tutorial, I had some sort of temporarily permanent scroll that let me cast flare during the tutorial instead of having the spell in my spellbook and when I was finished with the tutorial, the scroll disappeared and I only had heal minor wounds in my spellbook.So, while I was in the tutorial, I had to constantly re-equip the flare "scroll" to cast it, but once I finished the tutorial and purchased spells, I never had that problem again. Not sure if I actually purchased flare though. I may have gone straight for better spells.

That was a mod,I believe OOO, that changed that, apparently thinking that Flare was too powerful to start with...

you are totally right. And this is exactly the kind of issue that stems in my game. There is a permanent flare scroll inside my inventory, and I do not understand if that is supposed to happen. I mean, I removed Supreme magicka. I then started a new game.
Is it possible it is a vanilla problem?

But I'm not using OOO.

Ah, for anyone wondering, I found the source of the "going sneak" automatically. It's duke patrick mod, I was dodging the swords but I didn't realize it because I'm immortal. As soon as I kept playing the signs became clear.

I doubt it is a vanilla problem since I did not have that issue before I started using SM. But it is odd that the issue persists for you after you left the sewer and even odder still that it persists after you uninstalled SM. The only mods we have in common are the unofficial patch and SM, so I don't think its any of your other mods and I have never heard of such a thing in vanilla. Did you rebuild your bashed patch after you removed SM?