I am using the hosted Canonical Landscape to manage my Ubuntu servers. Recently, I migrated an Ubuntu 12.04.1 virtual machine from one host to another. After the migration, the server was unable to contact Landscape. Based on the Landscape documentation, I removed the server from Landscape, and re-registered it. It worked beautifully and the server is in contact with the service.
However, while the server was out-of-touch, several "Resynchronize computer" activities were created and were left in a Pending or In Progress status when the server was de-registered. They did not get removed when the server was removed from Landscape.
How can I remove these orphaned activities?
I have tried to manually cancel them, but the action buttons are greyed out when the task is opened.