Cannot see individual policies in client's 'Add to Exclude List'

Hi,

We're using NB 7.5.0.5, master is a Windows 2008 R2 server. 

In the Admin Console, when I go into a client's Exlude Lists I cannot see individual policies to choose to add the exclusion too - only <<All Policies>> appears. Why is this? At least one policy exists for all my Windows servers - Win2003 & Wind 2008  - but none of them allow me to choose from an individual policy. 

Thanks!