Yes, annoying! I guess it happens often enough for a note from Dictionary.com:
Pronunciation note:
Pronunciations of mischievous with stress on the second syllable: [mis-chee-vee-uhs] or, less commonly, [mis-chee-vuhs], instead of on the first: [mis-chuh-vuhs], are usually considered nonstandard. The pronunciation [mis-chee-vee-uhs], with the additional syllable, occurs by analogy with such words as previous and devious.