Index: /luci/branches/luci-0.8/modules/admin-full/luasrc/model/cbi/admin_network/dhcp.lua
===================================================================
--- /luci/branches/luci-0.8/modules/admin-full/luasrc/model/cbi/admin_network/dhcp.lua	(revision 3205)
+++ /luci/branches/luci-0.8/modules/admin-full/luasrc/model/cbi/admin_network/dhcp.lua	(revision 3796)
@@ -46,5 +46,9 @@
 s:option(Value, "leasetime").rmempty = true
 
-s:option(Flag, "dynamicdhcp").rmempty = true
+local dd = s:option(Flag, "dynamicdhcp")
+dd.rmempty = false
+function dd.cfgvalue(self, section)
+	return Flag.cfgvalue(self, section) or "1"
+end
 
 s:option(Value, "name", translate("name")).optional = true