So Disk Cleanup is the culprit? Thank you for the info. I had noticed two updates being installed on Win7 repeatedly but paid it little attention. As you say, no reboot required. Oh well, as long as the updates are present a re-installation shouldn't do any harm.
It was reported on SevenForums but no idea if other OS's are involved. I've only noticed it in my main 7 platform up until now.
Tested it once again today, did an elevated Disk Cleanup and sure enough, once again they are offered and even go through the motions of downloading and installing, quite bizarre.
Anyway, if one unchecks the item shown below, that will stop it from repeating. I wonder if MS will fix this on 14 April, Update Tuesday?
Anyone else reading this, it seems that this is restricted to Windows 7 as far as we can ascertain.
This has been patched btw.