Adding A Column To Access Database, Visual Studio Not Updating Column List

I have a project with a dataset of an access database file.

I opened up the DB file in access, added a column to a table, closed VS2010 & reopened and still it is telling me that the new column is not there in the Data Sources window, even after clicking the ref开发者_开发百科resh button.

I have re-opened Access and confirmed that I am editing the correct file & that the change made is there afterwards still but still no change in VS.

Any ideas what I have done wrong here / how to get VS to update with the correct table details?