This is indeed a bug. See these:
http://askubuntu.com/questions/15110...in-home-folder
And here is the bug reported on Launchpad:
https://bugs.launchpad.net/ubuntu/+s...dm/+bug/984785
Apparently there is no fix available yet.
Are you using Ubuntu One? The first link says it may be related to file transfers to Ubuntu One.
I have not had this problem, but I am running Lubuntu 13.04, not Ubuntu 13.04. I do not use Ubuntu One either.
Good pickup!
And welcome to the LQ forums!