Post Upgrade 4.1SP3 - Group Tree not Expanding in Crystal Reports

Hello Experts,

We have recently upgraded BOBJ from 4.0 SP 6 to 4.1 SP3.

What our users are seeing is that after a certain number of records the group tree navigation in the crystal report viewer no longer expands. This is occurring in both our DEV and PROD environments (sane bobj version).  In the below image, I had attempted to expand the items in the red circle, which do have sub items.  Rather than open the + disappears.  All of the items above the circle expand properly, all of the items below do not.  ANy ideas as to a possible cause / solution?

Thanks, Mark