I am not aware of any bulk or global method from a >FTW file
You could I guess go to each media item in the scrapbook and copy it then paste it into an image editing program and then save each file. Bit tedious and you could use the custom report to find all the media
Assuming there is a bug with FTMM importing a .FTW file from FTM 2005, I would be more inclined to open the 2005 with media in FTM 2012, ie the Windows version. This will get all the media and the correct links
Then use the File Migration Utility to get the Windows FTM file into FTMM
Bit messy but it should work
The developer are aware of the issue and as there is a patch coming out for FTMM very soon, maybe it has been fixed?