I have used 1.37 out of 8GB of space in Dropbox, 6GB of which is from referrals. I have been sent a shared Dropbox folder to add to my Dropbox but it takes me to a new plan page with the message " Your account is almost out of storage". I don't know the size of the new file but likely to be far less than 1GB. Why is Dropbox suggesting I have one 2GB? The plan says 8GB.