I noticed that every time I logged into a server I got the following:
This message was displayed even though no plugins were being pulled down from the Merchandising Server. Turns out I had forgotten the -allowadminTSupdates switch when running the updater.
A quick change to the command line of the receiver updater and a reboot sorted the issues... no more pops and plugins delivered as expected:
"C:\Program Files (x86)\Citrix\Receiver\Receiver.exe" -autoupdate -allowadminTSupdates -startplugins
Any questions, post below.