If it is your turn (not round, turn), then you can take a swift action, or an immediate action, but not both.
If it is not your turn (and you are not flatfooted), you cannot take swift actions, but you can take an immediate action, which eats up your swift action for your next turn (that point in combat when your character gets to perform most actions, such as moving, attacking, etc).
Cool, what you say is totally consistent with what I am saying actually. My question is not about WHEN you can take immediate actions but WHETHER you can take one IF you have already taken a swift in the round. What I am saying is this. Lets say nI DONT take a swift on my TURN. I CAN take an immediate and it uses up my swift for NEXT turn. Lets say I do take a swift on MY TURN. I CANT use an immediate. So, I can only use an immediate if I have NOT used my swift AND I lose my NEXT swift. So immediates are a tax as they should be. And what you have said doesnt address what it says on page 7 top left corner of rules compendium. You need to convince me that that "or" which in the previous sentence is used in the exclusive sense is NOW used in the inclusive sense.