diff --git a/README.md b/README.md
index e28a92aa..b80ecd5b 100644
--- a/README.md
+++ b/README.md
@@ -157,7 +157,7 @@ Sur une machine de DEV, lancer
 
     flask profile --host 0.0.0.0 --length 32 --profile-dir /opt/scodoc-data
 
-le fichier `.prof` sera alors écrit dans `/opt/scoidoc-data` (on peut aussi utiliser `/tmp`).
+le fichier `.prof` sera alors écrit dans `/opt/scodoc-data` (on peut aussi utiliser `/tmp`).
 
 Pour la visualisation, [snakeviz](https://jiffyclub.github.io/snakeviz/) est bien:
 
diff --git a/app/scodoc/sco_cache.py b/app/scodoc/sco_cache.py
index 53a26d77..9c20a213 100644
--- a/app/scodoc/sco_cache.py
+++ b/app/scodoc/sco_cache.py
@@ -46,9 +46,9 @@
 #  sco_cache.NotesTableCache.delete_many(formsemestre_id_list)
 #
 # Bulletins PDF:
-#  sco_cache.PDFBulCache.get(formsemestre_id, version)
-#  sco_cache.PDFBulCache.set(formsemestre_id, version, filename, pdfdoc)
-#  sco_cache.PDFBulCache.delete(formsemestre_id) suppr. toutes les versions
+#  sco_cache.SemBulletinsPDFCache.get(formsemestre_id, version)
+#  sco_cache.SemBulletinsPDFCache.set(formsemestre_id, version, filename, pdfdoc)
+#  sco_cache.SemBulletinsPDFCache.delete(formsemestre_id) suppr. toutes les versions
 
 # Evaluations:
 #  sco_cache.EvaluationCache.get(evaluation_id), set(evaluation_id, value), delete(evaluation_id),
diff --git a/app/scodoc/sco_preferences.py b/app/scodoc/sco_preferences.py
index 92b00a67..d83ca14f 100644
--- a/app/scodoc/sco_preferences.py
+++ b/app/scodoc/sco_preferences.py
@@ -1894,21 +1894,9 @@ class BasePreferences(object):
         """Returns preference value.
         when no value defined for this semestre, returns global value.
         """
-        params = {
-            "dept_id": self.dept_id,
-            "name": name,
-            "formsemestre_id": formsemestre_id,
-        }
-        cnx = ndb.GetDBConnexion()
-        plist = self._editor.list(cnx, params)
-        if not plist:
-            params["formsemestre_id"] = None
-            plist = self._editor.list(cnx, params)
-            if not plist:
-                return self.default[name]
-        p = plist[0]
-        _convert_pref_type(p, self.prefs_dict[name])
-        return p["value"]
+        if formsemestre_id in self.prefs:
+            return self.prefs[formsemestre_id].get(name, self.prefs[None][name])
+        return self.prefs[None][name]
 
     def __contains__(self, item):
         return item in self.prefs[None]
diff --git a/app/scodoc/sco_users.py b/app/scodoc/sco_users.py
index eaf43494..de154857 100644
--- a/app/scodoc/sco_users.py
+++ b/app/scodoc/sco_users.py
@@ -46,7 +46,7 @@ from app.scodoc import sco_etud
 from app.scodoc import sco_excel
 from app.scodoc import sco_preferences
 from app.scodoc.gen_tables import GenTable
-from app import log
+from app import log, cache
 from app.scodoc.scolog import logdb
 import app.scodoc.sco_utils as scu
 
@@ -226,6 +226,7 @@ def _user_list(user_name):
         return None
 
 
+@cache.memoize(timeout=50)  # seconds
 def user_info(user_name_or_id=None, user=None):
     """Dict avec infos sur l'utilisateur (qui peut ne pas etre dans notre base).
     Si user_name est specifie (string ou id), interroge la BD. Sinon, user doit etre une instance
diff --git a/app/views/scolar.py b/app/views/scolar.py
index a3a91303..79e9d198 100644
--- a/app/views/scolar.py
+++ b/app/views/scolar.py
@@ -306,6 +306,7 @@ sco_publish(
 @bp.route("/groups_view")
 @scodoc
 @permission_required_compat_scodoc7(Permission.ScoView)
+# @permission_required(Permission.ScoView)
 @scodoc7func
 def groups_view(
     group_ids=(),
@@ -319,7 +320,7 @@ def groups_view(
     formsemestre_id=None,
 ):
     return sco_groups_view.groups_view(
-        group_ids=(),
+        group_ids=group_ids,
         format=format,
         # Options pour listes:
         with_codes=with_codes,