Since we have the word recur, is it wrong to say reoccur?
from the Dictionary of Commonly Confused Words:
recur, reoccur--Recur, more widely used than reoccur, implies the repetition more than once of an event or experience, sometimes according to a definite pattern. Reoccur suggests a one-time repetition.
Corresponding nouns are recurrence and reoccurrence.
Recurrence is much more widely used.