Voted for the bug!
One more thing about your code

:
Code:
// MAP the translated folder name with the ZCS nanme
var transInbox = ZmMsg.inbox;
var transTrash = ZmMsg.trash;
var transJunk = ZmMsg.junk;
var transSent = ZmMsg.sent;
var transDrafts = ZmMsg.drafts;
// Now I replace translated labels to avoid 404 errors
var folderPath = obj.path;
folderPath = folderPath.replace(transInbox,'Inbox');
folderPath = folderPath.replace(transTrash,'Trash');
folderPath = folderPath.replace(transJunk,'Junk');
folderPath = folderPath.replace(transSent,'Sent');
folderPath = folderPath.replace(transDrafts,'Drafts');
You should add the Chats folder.