wrighty
Thalmor 3rd Emissary
Hold on a moment here, either the protection from magic is permanent or not, so the 25% racial protection from magic is in force, im not talking about stones or perks, just the racial ability, so therefore it must be protecting the breton from spells cast on himself, such as atronachs as mentioned, so it must also be the same for Alteration,(flesh armor) as that is also cast upon yourself, !!
magic resistance does not affect your summon spells at all, it is spell absorbtion which does, you get 30% spell absorbtion from the atromancy perk, 50% from the breton greater power and some from the atronach stone.
If you are a breton and use the spell absorption power, if you summon before you use the power your summon lasts 60 seconds which is the same duration as the power so you will not need to summon in those 60 seconds therefore the bretons racial power will not negatively effect you.