Dispelling magic

[AxeMental]

I understand that any scrolls and potions, active spells and cast spells will be subject to failing. However how would these be effected:
1. monster summoning I (say a group of orcs) turns a corner and attacks a group of adventurers if a disple magic spell is cast on them would they disappear.
What if they run into a wall of ice (after it had been cast).

2. If you cast a lightning bolt outside of the range of a dispel magic area of effect as the lighting enters will it dispel the entire spell, or would it stop the spell only in the area of effect, or would it not effect the spell since it says spec. that it prevents casting.
ex. a MU casts lighting bolt at palidan with dispel magic sword from 60 feet away (outside of the dispel magic area) would the lighting need to save vs. dispel or would it just go through.

[foster1941]

1. In both of these cases the spell has a duration and thus the magic is still active and subject to dispelling -- if they fall within the area of effect of a dispel magic spell the summoned creatures would disappear, and so would the wall (or at least the portion of the wall within the spell's AOE).

2. This is perhaps more a question about the dispel magic effect of a Holy Sword than the lightning bolt. Dispel Magic is normally an instantaneous spell that dispels magic effects in effect in the area of effect of the spell at the time it is cast. Thus, since a lightning bolt is also instantaneous, the only way for the former to effect the latter would be for the spells to take effect at the exact same time (represented by a tied initiative roll+casting time). In such a case I'd say the dispel would only effect the portion of the lightning bolt within the dispel's area of effect, but if the bolt extended beyond that area the remaining portion(s) wouldn't be affected. However, this still leaves us with the question of the Holy Sword's dispel magic effect -- is this always in effect or is it something that the paladin must activate as an at will ability? I'd tend to say the latter (and thus in order to effect a lightning bolt the effect would have to take effect simultaneously with the spell -- meaning that the paladin would either need to lose initiative or delay his action to match the casting time of the spell). But even if you say that this effect is always in operation, I'd still only have it dispel that portion of the bolt that falls within the dispel's area of effect (5' radius around the paladin) and that the portions of the bolt outside of that area would be unaffected.