I haven't had this problem. TrueCrypt encrypts each block independently, and Dropbox has typically been pretty good at just updating the deltas. The biggest p

I haven't had this problem. TrueCrypt encrypts each block independently, and Dropbox has typically been pretty good at just updating the deltas. The biggest problem I've had storing TrueCrypt volumes in Dropbox has been forgetting to unmount the volume when I move from one system to another, resulting in unsynced changes and lots of conflict files. One solution is to store your entire Dropbox directory within a TrueCrypt volume, but this is a bit cumbersome as you'd need to create a separate TrueCrypt volume on each system, and ensure that you have the volume mounted before running Dropbox (although this can easily be worked around with a launch script).