Paypal dispute - Actually sending the goods back to the seller

HI there
I've filed a Paypal dispute over a Laptop I bought from e-bay, after getting it professionally checked etc I've been told to post it to the seller.
At this point she'll refund me?
They haven't actually made any guarantees I'll get my money back, at the point I post it back she'll have £300 and her laptop back...I'll have a RMSD receipt.

Has anyone been in a similar situation?

My problem has similarities although the return address I was given doesn't exist and Paypal is refusing to refund me the amount I've lost in this transaction. They actually hamper my attempt to get a refund by not allowing me to send evidence to back up my claim, they're effectively protecting the fraudster by default.