It seems every time I update the game I get the error
Updater - Error
failed to rename <GAMEDIR>/tempfile to <GAMEDIR>/piigs/randomfile
If I keep running the updater it does eventually update, failing on different files, then downloading them again next time I run the updater until its all done.
However if you make a shortcut direct to the CityOfHeroes.exe and add '-project eucoh' to the end, you can bypass the patcher and go straight to the game.