Sorcerers and metamagic.

[bob le bob]

When a sorcerer using metamagic takes a full-round action to cast a single action spell does the spell take effect immediately or at the start of the sorcerer's next turn?

Bob le Bob.

 

[hong]

Immediately (assuming it's a spell that normally takes 1 action to cast). Using metamagic turns the casting into a full-round action, which is distinct from a full-round casting time. Basically the sorc gives up the ability to make a move or MEA while casting the spell.

 

[Dr. Zoom]

Hong is spot on, as usual. This has been clarified by the Sage and Tome and Blood, page 81, in case you need some reference.