can anyone help?

for a little while now i have been havin problems when playin live, basically i cant join a friends game and vice versa on rainbow 6 vegas 2 , nor can i private chat them (its ony 2 or 3 friends tho ) anyone know why this could be? also if someone else sets a game up and me and one of my friends join that i have probs connecting with i cant hear them , unless SOMEONE else starts a party (new thing from latest update) but then if i host a party they cant join it etc ,

tried deleting them as a friend then adding them again but to no effect , buggin the shit outta me now .

Any suggestions?

Scott