SVG export results in missing and misaligned objects

Hello,

We use CorelDRAW to produce technical drawings, which are exported as SVG files for use in our custom software.  The exported SVG is often not representative of the drawing in CorelDRAW -- missing text, objects not in the same place, lines at different angles, etc.

Here is an example drawing in CorelDRAW:

Here is the exported SVG, loaded in Firefox 37.0.2:

Here are the SVG export settings that were used:

Changing the "Compatibility" setting doesn't change the results.

This problem makes CorelDRAW X6 unusable for our purpose.  Are there any solutions?  We have installed all of the available patches, to bring the version to 16.4.1.1281.

Exporting the same drawings as SVG files from CorelDRAW X3 is usually fine.

Any help would be greatly appreciated.