Strange dotted line in illustrator workplace.

[mar6]

Strange dotted line suddenly appeared to illustrator program when i started illustrator next day.

How can i get rid of it?
http://i24.tinypic.com/kdsapl.jpg

I made red circle around it in paint.

When i closed illustrator in evening everything was ok, and next morning that strange line was there suddenly and i just cant rid of it.

 

[IdahoFarmer]

Its related to the page tiling... you can remove this by going to View -> Hide Page Tiling.