Dear Artur,
Yes, I have tried your suggestion but it was not working. After many trial & error, I found that if I move the dimension element in CE5, it will change back to correct shape, but a different(wrong) shape in V8i.
The Left was the preferred shape and the Right one was the incorrect shape generated by .NET API.
I attached the dgn for your reference.
(Please visit the site to view this file)