New favorite lens and a question

Tried out my "new" 80-200mm Minolta HS lens this weekend and had a lot of fun. The best part was when a couple people asked what lens it was. "Minolta???"

Now for the question. My monitor at home was acting funny, and I am wondering if this pic seems a little dark. On one PC it looks great, but on another it looks underexposed and the faces look pretty dark (shadowed).