diff -r 3a5722420de7 tools/python/xen/xend/XendDomainInfo.py
--- a/tools/python/xen/xend/XendDomainInfo.py	Thu May 03 19:25:47 2007 +0100
+++ b/tools/python/xen/xend/XendDomainInfo.py	Sat May 05 10:34:15 2007 -0400
@@ -891,9 +894,12 @@ class XendDomainInfo:
 
         # Check if the rtc offset has changes
         if vm_details.get("rtc/timeoffset", 0) != self.info["platform"].get("rtc_timeoffset", 0):
-            self.info["platform"]["rtc_timeoffset"] = vm_details.get("rtc/timeoffset", 0)
+            rtc = vm_details.get("rtc/timeoffset")
+            if not rtc:
+                rtc = "0"
+            self.info["platform"]["rtc_timeoffset"] = rtc
             changed = True
- 
+
         if changed:
             # Update the domain section of the store, as this contains some
             # parameters derived from the VM configuration.