Same spell, different ID?
 

I've had a user complain that my add-on has the wrong spell ID for the Guard (the monk ability) and Resolve (the tank thingy) buff. According to him the add-on doesn't work correctly, but it's fine after he changes these numbers in my code.
That's all good and fine, except that the add-on definitely works as intended for me, showing both buffs correctly.
Is it possible that these buffs use different spell IDs on horde/ alliance? Or is there perhaps another perfectly logical explanation for this?

Things like this could change a spells id to a different one:

http://www.wowhead.com/item=85691/glyph-of-guard

Unlikely, but yes there should be a number of other explanations.

Ooh, damn... that's probably that.
But what could possibly change Resolve though?

I'm not really sure, but it's possible that Resolve's spell id is class dependent in some cases.

But as you can see in the changelog Resolve is recently changed so it might got a new spell id now:

http://www.wowhead.com/spell=158298/resolve#changelog

158298
158300
both are Resolve
I think the buff is the later