Many GNOME-based Linux distributions have switched to NetworkManager for WiFi connections. This doesn’t even try to connect until after you have logged in, because its client runs under your session. If Dropbox has been having trouble connecting on a distribution using NetworkManager with WiFi, it may be because Dropbox starts trying to connect before the network is started. A quick workaround involves adding a delay to Dropbox to make sure the network connection is active before Dropbox starts.

The directions have changed for the newest version of Dropbox.

  1. In Dropbox’s preferences dialog, uncheck ‘Start Dropbox on system startup’
  2. Open System→Preferences→Startup Applications
  3. On the Startup Programs tab, find Dropbox; click it and press Remove
  4. Press Add.
  5. Name the new entry “Dropbox” (or “Tom”, “Jim” or “Samantha”…)
  6. Enter in Command: bash -c ‘while ! ping -q -w5 -c1 www.google.com; do sleep 5s; done; dropbox start -i’
  7. Click Save, click Close, log out and log back in.

Ping added on suggestion from Håvard R.