Flex 3: manually sort a DataGrid after applying an automatic sort (clicking on the column header)

Question

Hi!

I have a DataGrid in Flex3 which I want to sort by means of clicking on the column header and then tweak this order using a manual sort, dragging and dropping items.

I have found out that once you use the column header to sort, there is no way to get rid of this behaviour (unless establishing the data provider's sort property to null and then refreshing the data), so no way to "re-sort" manually.

(Note: I'm using custom functions to sort the columns, but I think this is irrelevant)

Any ideas on how to achieve this behaviour I need (first sort automatically clicking on the column header, then tweak the order manually)?

Thanks in advance, Dani