Grapes are bad because they can supposedly cause a form of anemia. However, I have yet to find two websites stating the same thing about grapes. For saftey, i would say no grapes.
Here is a link to the Animal Poision Control Centre, they have al ist of items that you should not give your pets;
http://www.aspca.org/site/FrameSet?s...nts/M01947.htm