Moving inactive members to Deleted Accounts fails

[Snowhog]

vBulletin 4.1.10

Admin CP > Users > Prune / Move Users
Usergroup = Registered Users
Has not logged on for x days = 1095
Join Date is Before = blank
Posts is less than = 1
Order By = Last Activity

This results in 2432 inactive members. All are checked.

Action = Move Deleted Accounts

When I click on Go, I'm told: Invalid Action Specified followed by No Users Matched Your Query.

What am I doing wrong?