AutoCAD Mechanical cannot add up

[Anonymous]

Hi,

I have a recurring problem with objects being copied inaccurately when doing a basepoint/displacement copy using the mouse. 

For example say I have 2 equal sized squares each with all 4 corners on integer x,y coordinates, the squares are 100 units apart.  If I select one, type 'c' and select a base point on the first then the same corner on the second as the copy point I should get another square exactly 100 units from the second.  Instead the new square will be placed maybe 100.0004 units or 99.9997 units away.  Even more baffling is that the 4 corners of the new square will each be off by different ammounts so my square is no longer exactly square.

In a drawing with hundreds of polylines errors like this are of course cumulative and quickly become visible as lines that are not quite vertical or horizontal.  For a simple copy as described above I can avoid the problem by entering the copy displacement of 100,0 instead of using the mouse but that is not practical.

Not all drawings do this.  The drawings I am working on have a sheet border as a block in the layout that is derived from Microstation.  However all of the model content has been drawn in AutoCAD, only my clients border was ported across.

Any suggestions welcome.

Product Version: E.208.0.0, Autocad Mechanical 2011 Version 3

[Daniela_Koloszko]

The problem seems to be related to specific drawing with third party entities. Could you please upload the drawing where this problem is reproducible?