c# datagridview change current selected row

OK. With some further investigation, I have found that the following code does do the trick:
int i = aView.CurrentRow.Index + 1;
aView.CurrentCell = aView.Rows[i].Cells[0];

I am having some kind of threading issue, because I am trying to manipulate the DataGridView from within a separate user-defined class. I don't know enough about threads to resolve this, but at least I have got to the bottom of changing the CurrentRow issue.