Index: trunk/web/validation.py
===================================================================
--- trunk/web/validation.py	(revision 276)
+++ trunk/web/validation.py	(revision 277)
@@ -44,5 +44,5 @@
         return MAX_MEMORY_SINGLE
     machines = getMachinesByOwner(user, machine)
-    active_machines = [x for x in machines if g.uptimes[x]]
+    active_machines = [x for x in machines if g.uptimes.get(x)]
     mem_usage = sum([x.memory for x in active_machines if x != machine])
     return min(MAX_MEMORY_SINGLE, MAX_MEMORY_TOTAL-mem_usage)
@@ -56,5 +56,5 @@
 def cantAddVm(user):
     machines = getMachinesByOwner(user)
-    active_machines = [x for x in machines if g.uptimes[x]]
+    active_machines = [x for x in machines if g.uptimes.get(x)]
     if len(machines) >= MAX_VMS_TOTAL:
         return 'You have too many VMs to create a new one.'