"ghost" lines - Windows XP

[faber]

well, this time I report a strange behaviour occured under Windows XP release.
I was trying to check some corners that were not "joined": I mean that the two lines behaved like separate lines.
In fact zoomming in with mouse wheel I saw the truth: there was a very little gap between the 2 lines.
Just to better see what I was doing I continued to zoom the part but... suddenly one line became invisible!
I zoommed out and... voilà! There was again.
I zoomed in again, but it disappeared again.
Well, I had to got pleased with the latest visible "frame"...
However if I did left click around (when the line was invisible) I got it: I could see in the property editor panel that I caught it.
This is not the first time I meet this problem and always under Windows (but another XP release-now SP2"- and another hardware configuration).

The same drawing didn't cause the same problem under Mac OSX (Snow Leopard).

[andrew]

These are buffer overflows occurring under the somewhat limited drawing system of Windows when lines are drawn outside the screen area. They are annoying but they don't affect your drawing in any way, only its visualization.

[faber]

Maybe I found the reply myself (not sure 100%).

The precision of decimal format was set to 0.0000

Zooming step by step (using OSX) I see a frame where the lines are not joined together! but however I can still see them.

Using "quote" menu I try to measure the distance from point to point; it was 0.00001

maybe when I zooming under Windows I missed this "frame"; I mean that the step before showed the little gap, while the step after the gap was larger than the screen.

I am not able to explain myself the way I could select the invisible line...