It's odd that it is all your spellcasters. Check that they haven't got any armour. Other possibilities:
You may have been level drained to a low level, then forgotten to reallocate spells to your spell slots upon being restored?
You may have used up all your spells and not slept in a while?
You may have had a silence or deafness spell cast on your group?
Check your spell book to see what you've got memorised.
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Time is an illusion. Lunchtime doubly so.
Epona of The Laughing Hyenas
Proud winner of the 'Most Useless Post 250 Has Ever Seen' Award 2001. "I'd just like to thank my friends and family, without whom none of this would have been possible..."