How can I find out what is deleting my ~/.Trash folder?
Open Terminal.app
Type in (or better copy-paste ;): curl https://raw.github.com/gist/1043757/9b55d3ae174ea40a1ff3b031fec7f87c5a58aa0d/gistfile1.d &gt; usage.d 
Execute sudo dtrace -s usage.d


This will display every file deletion on your system. If you want to only display the deletion of "~/.Trash", add | grep .Trash to the last command.