The problem is the grid rendering in Spread is written probably using custom code, and it's not equipped with what UI Automation expects.

I have tested the Sample Explorer provided by GrapeCity here (http://spread.grapecity.com/Pages/Demos/) with UI Automation's Inspect tool, and once you get to the data grid itself, there's nothing shown in Inspect.

There's also this topic in GrapeCity's forums: Is Spread even supported in coded UI test which clearly states (2 years ago) it's not supported (as you known VS Coded UI also uses UI Automation as the underlying technology).

So, I guess it's not possible to automate Spread using UI automation (maybe they have their own system, you'd have to contact them).