Project Web App does not provision permissions correctly after creating connected SharePoint site

Hi,

I am trying to create an Enterprise Project using connected SharePoint site under Project Web App using a custom solution.

in the solution, after creating a sub-site (connected SharePoint site), I break the role inheritance (with copying role assignments).

web.BreakRoleInheritance(true);

Then, I associate those exiting groups to respective associated groups for the subsite.

e.g. groupA, groupB and groupC are existing groups.

web.AssociatedOwnerGroup= groupA;
web.AssociatedMemberGroup= groupB;
web.AssociatedVisitorGroup= groupC;
web.Update();

but after first publish of the project, the association gets replaced by default associated groups.

e.g. if I name the site as "ProjectXYZ", project web app creates the default associated groups "ProjectXYZ Owners", "ProjectXYZ Members" and "ProjectXYZ Visitors" and associates them to respected associated groups.
so, "ProjectXYZ Owners" becomes AssociatedOwnerGroup, "ProjectXYZ Members" becomes AssociatedMemberGroup and "ProjectXYZ Visitors" becomes AssociatedVisitorGroup.

thats the problem, why does the code i run for association gets override?

thanks for any clarification.

-Kmodi