To reproduce:
Select an add-on, rt-click, select delete. Confirm delete. Status bar shows "All Addons deleted", but all add-ons, even the one that should have been deleted are still shown in the list. I used Ctrl-D to rescan the directory, and checked Windows Explorer to confirm that they're still on disk.
2008-09-20 18:41:31 UTC in World of Warcraft UI Updater