Yesterday I was having problems with my client, it was giving me an error message in Chinese. So I switched it back to American and updated. After that I moved it back to Chinese and I got the message: Unable to validate wow version and that perhaps some files were corrupt.
I decided to start over and get a new client, so I uninstalled and downloaded a new client from Blizzard. I did the usual steps of changing the config and the launcher files, and adding the new fonts. It was still connnecting to USA, I had to change the line:
Set locale "enUS" to "zhCN"
Now it connects to China but I'm getting the exact same error message as before as a launcher screen! I will post a screen shot after this if I can. I don't know what it says as it is in Chinese. My only idea is that the US version is at a slightly later patch and it won't work. I could try a manual install and build patches slowly but it should be the same.