strange objects

["A.M.Deganutti" <amgdega livecom it>]

Since the very beginning (a few months ago) of my use of Gnumeric I get strange
invisible objects in my worksheets: the mouse pointer turns from cross to arrow
and on click a second series of row and column headers appears... together with
some circular dots which show a box with "0,0x0,0 pts 0 x 0 pixels" at pointer
contact.
How can I get rid of that?
(I tried for hours!)
Thanks for any help,
Gingalone