Maybe going to your Tableau Server's admin page and looking under the link Background Tasks would give yo ua hint of the problem. We had a case where a scheduled refresh was not able to complete successfully due to an "out of memory" on the machine. Have a look at the tooltip for the specific datasource/workbook task you are experiencing problems with.
Hope this helps,
Thanks Vlad. Doesn't appear to be the issue though.
When connecting to a new data source do you normally publish it first and then connect to the published source and then create the source. I have been connecting to a data source and then creating the report and then publishing it. Does that make sense. perhaps the fact that I am not connecting to the data source is the issue?
If you publish the data source separately from the workbook it can be used by other reports also, but may be totally separate from the report you have created originally. To clarify a bit:
1) You open Tableau, make a live connection to your database, then create an extract, then publish the whole workbook (from Server->Publish workbook...), then in the dialog box you select appropriate refresh schedule and authentication options. This scenario publishes the report and the data for this report only, and it will update the data as you wish.
2) If instead of publishing the whole workbook, you right-click the conection and publish it as a data source and add this to a refresh schedule, then this is a piece of data you may reuse in other workbooks you create, but has nothing to do with the report you already made.
I believe you either have to use option 1 above, or, after you publish your separate data source, create a new workbook off it, and then publish this to Tableau Server to get your desired result.
Hope this helps a bit...