diff --git a/slack/im.py b/slack/im.py
index 271f1a9..9c12faa 100644
--- a/slack/im.py
+++ b/slack/im.py
@@ -10,10 +10,11 @@ class IM(threads.Thread):
     def __init__(self, json):
         threads.Thread.__init__(self, json)
         self.api_history = "im.history"
-        self.api_info    = { "call" : "im.open", "ret" : "channel" }
+        self.api_info    = { "call" : "im.info", "ret" : "im" }
         self.api_mark    = "im.mark"
         self.__uid       = json.get("user")
         self.__user      = users.info(self.__uid)
+        self.__im_open   = None
 
     def name(self):
         return "Chat With %s" % self.__user.name()
@@ -22,8 +23,15 @@ class IM(threads.Thread):
         return "%s/messages/@%s/" % (base, self.__user.user())
 
     def call_fetch_info(self):
-        return api.call(self.api_info["call"], token = auth.token(),
-                            user = self.__uid, return_im = True)
+        ret = threads.Thread.call_fetch_info(self)
+        if ret["ok"] == True:
+            self.__im_open = ret[self.api_info["ret"]]["is_open"]
+        return ret
+
+    def is_member(self):
+        if self.__im_open == None:
+            self.fetch_info()
+        return self.__im_open
 
 
 def list():
diff --git a/slack/threads.py b/slack/threads.py
index cfc15ef..8212748 100644
--- a/slack/threads.py
+++ b/slack/threads.py
@@ -37,7 +37,6 @@ class Thread:
         if json["ok"] == True:
             self.__unread  = json[self.api_info["ret"]].get("unread_count", None)
             self.__last_ts = json[self.api_info["ret"]].get("last_read", None)
-            self.__id      = json[self.api_info["ret"]].get("id", 0)
 
     def fetch_messages(self):
         json = api.call(self.api_history, token = auth.token(),