SMP Logs filling up with 'GetClientTaskServers' errors

Morning,

I am seeing a constant feed of Warnings detaling the following:

The handler 'GetClientTaskServers' is failed to process request. Called by unknown endpoint '54ade2fc-e25e-4206-ab6b-d920aabfbb6f'.

I found the resource associated to the GUID which was an unmanaged XP system which no longer exists on our domain and deleted it from the filter "All computers with no SM agent", but it continues.

We are running SMP 7.5 SP1 with the latest Hotfix on Server 2008 R2 SP1.

Any ideas would be welcome.

Thanking you in advnace.