Concentration and line of effect

[Vindicus]

I have been searching all over and can't seem to find if I still need line of effect to maintain a spell with concentration. The problem our group is having revolves around our cleric wanting to use a summon spell that requires concentration throughout its duration and if someone cast a resilient sphere spell around him, can he maintain the summon spell even though he doesn't have line of effect (but does have line of sight). Citation would be preferred on this since our DM is a stickler.

[Curmudgeon]

Yes, you need line of effect to maintain a spell. From page 80 of Rules Compendium:
You must have line of effect to any target that you cast a spell on or to any space in which you wish to create an effect. An ongoing spell is a magical effect. You don't need line of effect to the summoned creature continuously, but you do need it during the standard action each round you concentrate to maintain the spell.

[Deophaun]

Yes, you need line of effect to maintain a spell. From page 80 of Rules Compendium:
How does that quote support your conclusion? It only talks about targeting and creating effects. It says nothing about maintaining those already in existence.