Weird prob in 2012 - short lines wont draw, long ones do

[unearthed]

Just this morning drawing simple 2D polygons and lines - short lines just vanish when when I finish the line  - yes all classes are on.

 

Lines they keep vanishing until the line length is about 35 metres., also small polygons with say 7 vertices are reshaping themselves to a smaller poly of 3 vertices.

 

This occurs with snaps on or off. Units metres, precision 0.001

Anyone seen this? No changes to system recently.

 

Windows 10 Home 64bit, not networked. VW2012 update4

Edited February 21 by unearthed

[Pat Stanford]

Do you possibly have a snap grid set to a large value? If you do and are drawing lines that are not at least 1/2 of the snap grid length then they won't draw.

[unearthed]

@Pat Stanford  Thanks. Turns out I had polyline button live rather than 2D polygon, not a problem I've managed to trigger before all the way since ~2005.