the Redline panel can't be loaded correctly when user access it by 'go to previous task executed'

[liuar]

1. first, click 'Redline' and then panel displayed in the task panel
   
2. next, click 'Measure' button. Measure displayed in the task panel
   
3. after that, click the 'go to previous task executed' (the left arrow icon) in the task panel
   

result: the Redline panel is not loaded correctly. most of the buttons have no response when user clicks it.

expected result: the Redline panel works well.

walkaround: user click the 'Redline' button on the toolbar

[jng]

Replacement of the Redline widget has invalidated this ticket.