when i got my research fellowship the reaction of many phd students to me changed quite dramatically. they were quite clearly jealous and i felt excluded from stuff after that :(

Hi there,
you are not alone. I have experienced that too, but take that in your stride, they are jealous because they see you as a threat. Go to your advisor to discuss your ideas . This can also be an opportunity to establish a good personal and professional relationship with him/her. I am sure your advisor will give you honest opinions on papers etc...your profs are your best bets in such cases..and along the way you may impress quite a few.