TRIM periodically locks up AutoCAD

[hencoop]

I've had a different problem with TRIM before.  This problem is significantly different.

AutoCAD automatically initiates a REGEN and completely locks up while cranking the CPU heavily.

When this happens it is ALWAYS during a TRIM command.

The last visible messages at the command prompt are:

    Updating Indexes for block *Model_Space

    Done.

    Updating Indexes for block FutureSchool-82

    Done.

    Regenerating model.

The screen blacks out because of the regen and the regen is NEVER completed.

Performance Graph at start of lock up:

Threads affecting CPU Usage (Multiple MSVCR110.dll instances):


Performance Graph much later after lock up began:

[schroederC3D]

Does this happen on relatively simple geometry?  A line and a circle for example?  

[hencoop]

It has been happening with lines and polylines with arcs.

The file is over 16MB and was received from another firm.  It has been audited and even recover was run on an autosave file after one lock-up and forced crash.  I've been trying to remember to use BREAK instead of TRIM.  I have not had any problems with BREAK.

[hencoop]

UPDATE:

I was in a conference for awhile this AM while the problem drawing remained open.  When I returned it had locked up as before.  I had NOT used the TRIM command.  It now appears that this problem happens when autosave is triggered.