Dropbox not updating mountain lion
If your Mac exceeds a predefined temperature, Power Nap operations are suspended so that your Mac doesn't overheat. The default setting is on if your desktop Mac uses flash storage (not including Fusion Drive).
After you’ve sure you have the latest version of OS X installed and i Cloud configured to use the same account on all Macs you want to sync between, you can proceed.
Dropbox also lets me selectively sync files, so some files are only on my old Power Mac G4 and G5, some only on my Intel-based Mac mini and Mac Book.