DataGridView VB.NET Lat Column Resize

[theamesy]

I have a datagridview on a windows form, AllowUserToResizeColumns is
set to false, it has 3 columns, as you'd expect i cant resize the
columns, but i CAN resize the last column?

I have column headers visible set to true, and i can drag the far end
of the final column back n forwards.

If i set column headers visible to false, then i have the ability to
drag from the area where the rows are!

Any idea why this is happening? I set AllowUserToResizeColumns to
false cause i dont want my users to resize the columns as the name
suggests, so why allow them to resize the last column??

Cheers