Question about Dispel Magic (in General)

I spent 53k for enlisting a new minion, and got about 27k exp. I used it to train Dispel Magic. Why my dispel magic make my other minion AMF fizzles? So I replaced DM it with Protection. At the next battle, My enemy's DM made my protection fizzles while my AMF was still working.
Is it because my DM level was higher than my AMF and my enemy's DM was lower than my AMF but still higher than my Protection?

To summarize what I think about it:
1-st battle: my DM > my AMF
2-nd battle: my AMF > my enemy's DM > my Protection.

DM seems like affecting all enchant including casted by friendly minions

53k spent for just a suicide, what a poor newb I am!

DM can dispell own offensive enchantments(EC and AMF) as well as enemy's defensive enchantments(Prot, VA, GS, Haste, GA, AS).

Your own DM affects your EO while an opponents DM affects your ED.

These EO and ED things explain all I need to know, thank's for the answers.