Is that workbook in your screenshot using a published data source?
Are you still having this issue?, I have this working with Desktop 10 using extracts hosted on tableau server 10.
If you are using a blank sheet (as I am) to show the data update time, you have to have a measure or dimension in the sheet from the data source you are interested in. My solution to this is to create a calculated field called Data Update Dummy Calc as follows:
if false then ""
add this to rows then exclude the nulls. Now you can create the title with the Data time and Name. with nothing on rows or columns tableau does not know what data source you are referring to. If you have more than one data source for the workbook, make sure to create the calculated field in the data source for which you want to display the info.
hope this helps
We have that on all our dashboards so the end user know how up to date the data is that they are looking for. We created a simple worksheet that has this information in the title.
Then we added that to the top right corner on our dashboards shown here. Top left would just be the current date.
We have this sent into a template so people can use so things have the same look an feel.
One thing to note is that if you dashboard has multiple data sources presented on it then you need to think about what date you are gong to present the user to show when the data has been refreshed. or decision was to use the data source that is the primary one on the dashboard.