An argument came up in my last 3.5e game. Does the protection from evil spell (particularly Magic Circle against evil) protect against a succubus' (or anyone else's)suggestion spell. The protection from evil specifically states: "Second, the barrier blocks any attempt to possess the warded creature (by a magic jar attack, for example) or to exercise mental control over the creature (including enchantment (charm) effects and enchantment (compulsion) effects that grant the caster ongoing control over the subject, such as dominate person)." Suggestion, Hideous laughter and Irresistable dance are all Enchantment (compulsion) effects so are they blocked by Protection from evil? One opinion was no since the caster does not exert ongoing control since they cannot change what the recipient does on subsequent rounds. The other arguement is since the spells control the recipient for multiple rounds this counts as ongoing control since the recipient cannot change what they are doing for the duration of the spell.
Let me also explain what exactly happened during the game. The party had previously teleported away from a succubus. Upon our return the cleric had put up a Magic Circle against evil to protect us from charming. The hiding and invisible succubus cast Suggestion on the party's dwarven fighter suggesting that he was tired and should go to sleep. The dwarf failed his save and proceeded to go to sleep. The party's gnomish mage attempted a full round action to wake up the dwarf to no avail (DM ruled dwarf was asleep for the duration of the spell. So short of a successful dispel magic or similar effect the party's tank was out of the fight.) Needless to say without our big tank we had to flee again when the cleric's dimensional anchor failed to get past the succubus' spell resistance and the she broke free or resisted both of the mage's hold monster spells. So the arguement started about the magic circle and whether the dwarf should have fallen asleep.