When you sync a SEP 11 group using LDAP, it creates a subgroup where the clients actually go. That subgroup has an icon that appears to be a folder with a book on top of it; the book is tilted.
I had a group that was synched to the wrong LDAP OU - that LDAP OU should not have been synched at all. There were 10 clients in that group. Six of them are currently turned off; I did not get a response when I sent them a ping. Four were turned on - they responded to the ping. Those four, as it turns out, should not have had SEP installed at all - they are servers in our Citrix environment. (Let's not discuss the merits of that here - it's not up for discussion at this time.)
I deleted that subgroup that was incorrectly synched- the one with the icon of the book on top of the folder.
Question: Where did the clients go? Were they deleted as well?