I'm just not seeing what the problem is.
I assume you have a folder named "dropbox" at:
I would create a new folder for my FTM files
C:\My Documents\Dropbox\FTMDATA\and copy xxx2012.ftm here
Then, copy your Media folder and place it in the same place:
C:\My Documents\Dropbox\FTMDATA\xxx2012 Media\
Now, open that file in FTM at File > Open.
After this work session, this file should always be the file that opens because FTM opens the last file you have had open. If it doesn't, just look at the upper right corner of the Plan Workspace, right-click on the file name > open.
The Option in Options is just for NEW files - has no bearing on what the file opens when FTM is booted up.
Would this structure work for you?