Because of the frequent use of stock footage continuity errors would often be present. Perhaps the most noticeable example is completely different backgrounds before and after Andrea's transformation into Isis. Her first action after transforming was to take flight and a handful of stock takeoffs recur repeatedly throughout the series.
Being an ancient Egyptian deity reincarnated in human form, ideally, Isis should be fluent in the Egyptian language. However, she never speaks a word of Egyptian throughout the entire series; instead, she chants some of the silliest rhymes this side of Underdog (1964) to make her powers work.