"#=count#" not working in Footer Template

Hi - I want to add counts on a grid, and am copying code I've used on another grid with no problems.

Here is my column definition for the field in question, it gives me an error that "count" is not defined.

{ field: "SchoolYear", title: "Assessment Year", aggregates: ["count"], footerTemplate: "Count: #=count#", groupFooterTemplate: "Count: #=count#", groupHeaderTemplate: " #=value# - Count: #=count#"},

If I remove the "#=count#", and have this it renders fine, just no count of course

{ field: "SchoolYear", title: "Assessment Year", aggregates: ["count"], footerTemplate: "Count: ", groupFooterTemplate: "Count: #=count#", groupHeaderTemplate: " #=value# - Count: #=count#"},

What I don't understand is why I can use "#=count#" in the groupFooter and groupHeader templates and it's fine.

Any ideas?

Thanks

Lisa