I'm running ArcGIS Server 10.1 on a Windows box on Amazon, via remote desktop.
I've set up some services on which I have enabled caching using the Bing/Google/Esri scheme. I explicitly set these to Update Cache Manually.

For some reason, ArcGIS Server is changing these services to Update Cache Automatically. If I change it back to Manual, then immediately re-open the dialog, it has reverted to Automatic. If I choose View Cache Status, it's shown as "Tile Generation is in progress". Cancelling the tile generation has no effect - it immediately restarts.
I am creating these services by first creating *.sd files, in which I specify the cache levels and that I wish for Manual cache generation, then creating ArcGIS Server services from the *.sd files.
Why are these services changing irrevocably to Automatic cache updating?
Thanks