Hi,
I haven'T read the hole board, so it's possible that someone wrote the same.
I think the DC for Casting Spells when ...
Entangled: If you want to cast a spell while entangled
in a net or by a tanglefoot bag or while you’re affected by a
spell with similar effects, you must make a DC 15 Spellcraft
check to cast the spell. You lose the spell if you fail.
... is to low. Entangled is much the same like grappled. So I think a DC of 15 + Spell level is the better choice.