Can I re-freeze fruit?
Basically, you can refreeze the raspberries.
When a fruit or veg. is frozen, the water inside the plant cell expands, and bursts the cell wall, which is why there is so much 'juice' when you thaw.  If you refreeze, you can be sure that the raspberries will freeze into a giant block. If you are using them to make a sauce or a jam, this is not significant. That being said, if you are using frozen raspberries in the first place, you are obviously not looking for a perfectly intact raspberry, you are using them for some other purpose. Therefor, refreezing is no big deal. I recently answered another question about freezing and refreezing, and how it is basically a myth that it renders the refrozen product inedible. Any time you freeze you know that you are not going to get 'exactly' the same product when you thaw it, and the same goes with refreezing, there is always a 'slight' degredation of the product with each successive freeze (do you like my liberal usage of quotes?)  You won't poison yourself or anything like that, you should have no worries.

That being said, what are you doing with the berries? Certainly a refrozen raspberry should be no worse that a raspberry frozen once.