Viewports

[maria lemos_diaz <mlourdes@xxxxxxxxxxxxxxx>]

 To the Ferrets's Users :
 
 When i make a mistake in a viewport, i give "clear viewport ul"(par 
 example) and denn i repeat this viewport again. At the end i print
 the four plots together. But at viewport ul the second viewport ul 
 is  printing over the first viewport ul, that i cleared bevor.
 How can i to avoid it?
 
 Thanks in advance
 
 Maria