Mal Malenkirk said:Heck, no!
Freedom of movement protects against any form of magic that impedes movement.
Aside from that general protection, it also allows for normal movement under water.
There is nothing in the spell description that would allow to infer that it protects from being grappled.
This spell enables you or the creature you touch to move and attack normally for the duration of the spell, even under the influence of magic that usually impedes movement...
WaterRabbit said:
IMHO, Freedom of Movement only applies to magical effects and while underwater. I would allow it to negate the effects of quicksand and other natural type of stuff. I would probably allow a +8 circumstance bonus to Escape Artist checks to break physical restrains and grapples. It would not be an instant freedom however.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.