Please never store Truecrypt files in dropbox. I have tried this and it does not work as mentioned.
A small additional file changes the encrypted file so much that it causes dropbox to sync a large change through to the server although dropbox only sync's changes.
True. encFS is much better choice. It can be transparently mounted as regular folder in linux but I don't know if there is a windows way of accessing to it.
As an alternate to Truecrypt volumes, I use Windows Scheduler to run batch files that create 7-zip archives and copy them to my Dropbox folder. 7-zip can create AES-256 encrypted archives.
I still use dropbox + truecrypt, but it definitely does NOT work as mentioned. I just update the truecrypt volume so infrequently thats its not a huge deal to upload the whole thing (still cant complain about free cloud storage with no bandwidth costs)
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).
A small additional file changes the encrypted file so much that it causes dropbox to sync a large change through to the server although dropbox only sync's changes.