Colin --
In Project Web Access, when you click on the black header at the top of the
column, you will apply sorting to the data in that column. The default
sorting on the Tasks page is an Ascending sort on the Start Date column. To
indicate that sorting has been applied to a particular column, you should
see a tiny gray arrow to the left of the column name in the black column
header. If the arrow points up, the sort is Ascending; it is points down
the sort is Descending. If you do not see the gray arrow in the Start Date
column, then try clicking the column header and then see if the tasks now
match the order in the project. Hope this helps.