Comment 3 for bug 699128

Grid settings: Enable visible grid, 10 mil spacing.
OS: Fedora Core 5
WM: Gnome 2.14

As far as the trackpad, there is no physical contact between my hand and the pad when I click the left button to place the line segment. If my X-server is somehow tranlating a mouse click into a mouse click plus trackpad scrolling, its not doing this for any other program (and I have other grid based drawing programs). Nevertheless, I will attach the xev output.

The effect becomes more pronounced as the view is zoomed out. For example, if I zoom out to the point where a 'signal' sized line (10mil I think) looks only 1 pixel wide, I find it very difficult to draw a square; the random 'jumping' causes most of the vertecies to be placed at a point just to the left or right of where I clicked giving a short 45 deg line segment.

Additionally, there does not seem to be any way to turn auto-scrolling off in the preferences; if I set the auto pan speed to zero, it just automatically defaults it back to 1. So, I updated 'src/hid/gtk/gui-config.c' and changed line 260 from this:

  ghidgui->auto_pan_on = TRUE;

to this:

  ghidgui->auto_pan_on = FALSE;

and recompiled.

This has fixed my problem as far as I can tell. This also rules out any strange 1995 era X server/mouse interaction. This smells like an edge case triggering the auto pan.