Originally Posted by canadianjameson
Also, one is a PC and one is a MAC - am I just asking for trouble??
No, up until I got my iMac, I was using a PC as my desktop and a MacBook Pro laptop and with this method I had no problems across the different operating systems. Different operating systems do not impact the syncing process.
KEY HERE as DoctorOhh has pointed out is to NEVER have both versions of Calibre opened at the same time AND always let Dropbox fully sync before opening up Calibre. If you remember nothing else, remember these two items.