Constraining of component using Toolkit

Hello

We are using API ProAsmcompConstraintsSet() to constraint assembly component. There is two constraint to be set. One is Axis to Axis and other one is surface to surface. ProAsmcompConstraintsSet() is working fine if we ask end user to select four references but it fails and gives general error if selection objects are found through different API rather than asking user to select. Any idea of this failure will help us to proceed further.

One more information : Selection objects found by API are same as what user is selecting. This has been varified using ProselectionHighlight() API. This observation is blocking our path as we are not getting how to proceed. Selection to be done by user and selection object manipulated by different API (to constraint component) are same.

Thanks in advance.

Regards

Ketan