Is it possible to remove the column sort arrows from columns that have been set to not be sortable (as in code below).

Currently with this code the arrow appear so that when user mouses over the column header. This obscures the column (if it's small) and gives the user a drop down which is greyed out anyway.

Can this be removed or can anyone suggest a workaround?

Thanks

 <rich:column sortable="false" width="40px" label="Time">
 ......
 </rich:column>