Single Category Blog Page Not Working

Hello there,

I’m using Canvas 5.0 Theme and I’ve tried creating a single category blog page using the following approach:

1) Created new page using blog template.
2) Then I added a custom field to this page called “query_args” (without quotes) with the value of “cat=xx” (without quotes), where xx is the category id.
3) Finally I added to page to my primary navigation.

But it’s not working…any ideas?

Thank you for looking if you got this far. ??