Does anybody know why, if I open an AutoCAD drawing with IntelliCAD and then save it, why when reopening the drawing with AutoCAD there are masses of errors in the drawing that cause all manner of problems when binding and plotting?

Shown below is a small example of the kind of thing I mean:

Command: audit

Fix any errors detected? [Yes/No] <N>:
832 Blocks audited

Auditing Entities Pass 1


DXF Name Current Value Validation Default
AcDbLeader(4A6) annotation id Not-Null Null
AcDbLeader(4AB) annotation id Not-Null Null
AcDbLeader(114D) annotation id Not-Null Null
AcDbLeader(114F) annotation id Not-Null Null
AcDbLeader(1150) annotation id Not-Null Null
AcDbLeader(1151) annotation id Not-Null Null
AcDbLeader(1152) annotation id Not-Null Null
AcDbLeader(1153) annotation id Not-Null Null
AcDbLeader(1157) annotation id Not-Null Null
AcDbLeader(1158) annotation id Not-Null Null
AcDbLeader(115A) annotation id Not-Null Null
AcDbLeader(115B) annotation id Not-Null Null
AcDbLeader(115C) annotation id Not-Null Null
AcDbLeader(115D) annotation id Not-Null Null

Pass 1 45680 objects audited
Pass 2 45680 objects audited
Pass 3 56600 objects audited
Total errors found 14 fixed 0