Seems to be a problem in the 64 bit version of Dropbox I'm trying to install. On a fresh install of 12.10 I need to be able to set a different path for the Dropbox directory (not the standard placement in Home).
Although I’ve done this before, here when I try to change it in the advanced settings it leaves the default directory. Can’t get it to actually change to a different drive/directory.
There is a workaround for that problem: You have to open the dialogue to choose a folder for your alternative dropbox location - there, in the top left corner, you'll find a button with three dots and a pen on it. Click on that button and type the exact path to the location you want Dropbox to put your Dropbox Folder. (eg. "/home/username/Backup/" for the Dropbox folder being "/home/username/Backup/Dropbox")
See Thread: http://ubuntuforums.org/showthread.php?p=12328311
