Neil - it appears that this may be a known issue as SAP release SAP Note 2266124 just last week - see https://websmp130.sap-ag.de/sap(bD1lbiZjPTAwMQ==)/bc/bsp/sno/ui_entry/entry.htm?param=69765F6D6F64653D3030312669765F7361…
(hope that link works) or try https://websmp130.sap-ag.de/sap/support/notes/2266124 - SMP logon - looks like it is planned for a patch