diff --git a/gestion/ldap_crans.py b/gestion/ldap_crans.py
index 34502833..ef352cde 100755
--- a/gestion/ldap_crans.py
+++ b/gestion/ldap_crans.py
@@ -1737,10 +1737,18 @@ class adherent(base_proprietaire):
         if uidNumber:
             if self.exist('(uidNumber=%s)' % uidNumber):
                 raise ValueError(u'uidNumber pris')
-        else:    
-            uidNumber = 1000
-            while self.exist('(uidNumber=%s)' % uidNumber):
-                uidNumber += 1
+        else:
+            pool_uid = range(1001,9999)
+            random.shuffle(pool_uid)
+            while len(pool_uid) > 0:
+                uidNumber = pool_uid.pop()  # On choisit une IP
+                if not self.exist('(uidNumber=%s)'):
+                    # On a trouvé un uid libre
+                    pool_uid.append(uidNumber)
+                    break
+            if not len(pool_uid):
+                raise ValueError(u'Plus d\'uid disponibles !')
+
         try:
             self.lock('uidNumber',str(uidNumber))
         except:
@@ -2224,15 +2232,15 @@ class machine(base_classes_crans):
                     pool_ip.append(ip)
 
             # On va prendre choisir une IP au hasard dans le pool des IP dispo
-            ip = ''
             random.shuffle(pool_ip)
             while len(pool_ip) > 0:
                 ip = pool_ip.pop()  # On choisit une IP
                 if not self.exist('ipHostNumber=%s' % ip):
                     # On a trouvé la première ip libre
+                    pool_ip.append(ip)
                     break
 
-            if ip =='':
+            if not len(pool_ip):
                 raise RuntimeError(u'Plus d\'IP libres dans %s.' % string.join(net,' et ') )
             
         else: