AutoCAD 2004 3d model, need to export to STEP or IGES, need expert advice

I have a 3d solid (with surfaces) model in AutoCAD 2004 (which I can barely turn on) and I need to export it to STEP format so I can open it with CATIA.  I tried it using the EXPORT - STEP and IGES options.  When the command-line interface askes for a setup file, I just hit enter and it went happily on and made a model.  When I open it some solids are missing.  I can't find any docs that mention this setup file.   Here's the step REPORT, at the end:
~~~~~~~~~~~~~~~~~CONVERSION SUMMARY~~~~~~~~~~~~~~~~~

 OK = Transferred
 KO = Not transferred
 NS = Unsupported
 OUT = Out of size
 DEG = Degenerated
 INV = Invalid

 ---------------------------------------------------------------------
|  Entity Type          |  OK   |  KO  |  NS  |  OUT  |  DEG  |  INV  |
 ---------------------------------------------------------------------
| ADVANCED_FACE               | 16614 |    1 |    0 |     0 |     0 |     2 |
| MANIFOLD_SOLID_BREP       |   164 |    0 |    0 |     0 |     6 |     0 |
| BREP_WITH_VOIDS              |     6 |    0 |    0 |     0 |     0 |     0 |
| LINE                                   |    23 |    0 |    0 |     0 |     0 |     0 |
| CIRCLE                                |     2 |    0 |    0 |     0 |     0 |     0 |
| CURVE_BOUNDED_SURFACE  |     0 |    0 |    6 |     0 |     0 |     0 |
 ---------------------------------------------------------------------
|  Result                               | 16809 |    1 |    6 |     0 |     6 |     2 |
 ---------------------------------------------------------------------

Also (this may be another clue) the first time I started AutoCAD opening this model I got some errors about missing 'enablers'.  Does this mean the creator of it used some 3rd party special modeling functions so the entire model won't open with std AutoCAD?

Here is the error:
The drawing you have opened or referenced contains
custom objects created by an unavailable ObjectARX
application. You do not need the original application
to display proxy representations of objects that were
saved in the drawing. However, many manufacturers,
including Autodesk, provide object enablers that also
allow you to edit these objects.

Visit the AutoCAD Object Enabler Assistant web
page to locate Autodesk object enablers or contact the
software publisher about object enablers for other
applications.

Note:  If your computer has internet access, verify that
Check Web for Live Enablers is selected in the Options
dialog box on the System tab to have AutoCAD
automatically search the Live Enabler website for the
appropriate object enabler.

Missing Application : AutoSurfServices
Total Number of Proxies : 7
Number of objects (no graphics) : 1
Number of entities with no graphics : 0
Number of entities with bounding box graphics : 0
Number of entities with real graphics metafile : 6

Missing Application : AutoSurfResolverServices
Total Number of Proxies : 1
Number of objects (no graphics) : 1
Number of entities with no graphics : 0
Number of entities with bounding box graphics : 0
Number of entities with real graphics metafile : 0

Missing Application : AdGrefServices
Total Number of Proxies : 1
Number of objects (no graphics) : 1
Number of entities with no graphics : 0
Number of entities with bounding box graphics : 0
Number of entities with real graphics metafile : 0

Missing Application : MApiSurfServices
Total Number of Proxies : 1
Number of objects (no graphics) : 1
Number of entities with no graphics : 0
Number of entities with bounding box graphics : 0
Number of entities with real graphics metafile : 0

Missing Application : MApiAdServices
Total Number of Proxies : 1
Number of objects (no graphics) : 1
Number of entities with no graphics : 0
Number of entities with bounding box graphics : 0
Number of entities with real graphics metafile : 0

I followed the software's suggestion and checked the option to automatically get enablers.  It downloaded something but I don't know if it really fixed anything.  I used the very old AutoCAD a long time ago for 3d, and I'm a very experienced 3d modeler in CATIA but I'm pretty helpless in this version of AutoCAD.  

IGES makes a huge model with horribly large numbers of very narrow surfaces.  I think STEP will be better because it keeps the solids.  The big remaining problem is that a chunk of the model is missing in STEP.  It loos pretty good otherwise.   My guess is it could be something to do with non-standard entities created in 3rd party software but I don't know.