diff --git a/devstack/env_rc.py b/devstack/env_rc.py
index a90a6be9..39e2fa43 100644
--- a/devstack/env_rc.py
+++ b/devstack/env_rc.py
@@ -144,7 +144,6 @@ alias ec2-upload-bundle="ec2-upload-bundle -a ${EC2_ACCESS_KEY} -s ${EC2_SECRET_
     def _generate_nova_env(self):
         lines = list()
         lines.append('# Nova stuff')
-        key_params = keystone.get_shared_params(self.cfg)
         lines.extend(self._make_export_cfg('NOVA_VERSION',
                                 ('nova', 'nova_version')))
         lines.extend(self._make_export_cfg('NOVA_CERT',
diff --git a/devstack/utils.py b/devstack/utils.py
index 5954b39b..c99464ec 100644
--- a/devstack/utils.py
+++ b/devstack/utils.py
@@ -351,6 +351,30 @@ def param_replace_list(values, replacements, ignore_missing=False):
     return new_values
 
 
+def params_find(text):
+
+    #knock off all comments
+    cleaned_text = list()
+    for line in text.splitlines():
+        line = line.strip()
+        if len(line) == 0:
+            continue
+        if line.startswith("#"):
+            continue
+        #TODO: handle inline comments??
+        cleaned_text.append(line)
+
+    found_params = set()
+
+    def finder(match):
+        found_params.add(match.group(1))
+
+    for line in cleaned_text:
+        PARAM_SUB_REGEX.sub(finder, line)
+
+    return found_params
+
+
 def param_replace(text, replacements, ignore_missing=False):
 
     if not replacements:
@@ -364,19 +388,25 @@ def param_replace(text, replacements, ignore_missing=False):
     else:
         LOG.debug("Performing parameter replacements (not ignoring missing) on text [%s]" % (text))
 
-    def replacer(match):
-        org = match.group(0)
-        name = match.group(1)
+    possible_params = params_find(text)
+    LOG.debug("Potential parameters are [%s]" % (", ".join(possible_params)))
 
-        v = replacements.get(name)
-        if v is None and ignore_missing:
-            v = org
-        elif v is None and not ignore_missing:
-            msg = "No replacement found for parameter %s" % (org)
-            raise excp.NoReplacementException(msg)
-        else:
-            LOG.debug("Replacing [%s] with [%s]" % (org, str(v)))
-        return str(v)
+    if not ignore_missing:
+        for r in possible_params:
+            if r not in replacements:
+                msg = "No replacement found for parameter %s" % (r)
+                raise excp.NoReplacementException(msg)
+
+    def replacer(match):
+        org_val = match.group(0)
+        param_name = match.group(1)
+        replacement_value = org_val
+        if param_name in possible_params:
+            replacement_value = replacements.get(param_name)
+            if replacement_value is None:
+                replacement_value = org_val
+        LOG.debug("Replacing [%s] with [%s]" % (org_val, str(replacement_value)))
+        return replacement_value
 
     return PARAM_SUB_REGEX.sub(replacer, text)
 
diff --git a/stack b/stack
index 76e7a194..23daf935 100755
--- a/stack
+++ b/stack
@@ -92,8 +92,10 @@ def run(args):
     if not rootdir:
         print(utils.color_text("No root directory specified!", "red"))
         return False
-    (rep, maxlen) = utils.welcome(_WELCOME_MAP.get(action))
-    print(utils.center_text("Action Runner", rep, maxlen))
+
+    #welcome!
+    (repeat_string, line_max_len) = utils.welcome(_WELCOME_MAP.get(action))
+    print(utils.center_text("Action Runner", repeat_string, line_max_len))
 
     #here on out we should be using the logger (and not print)
     start_time = time.time()