All Inventory tasks Failing with Return code -1

Hello,

After any software delivery package runs on Client machines the "Gather Add / Remove Programs Inventory" task fails with a return code of -1

This is affecting both Win 7 and XP clients in our organisation.

Any ideas on why all tasks like this are failing? Even running them as a seperate task from the console isnt working!

Attached are a couple of screenshots showing the task history and job itself.

Thanks in advance.

John