Delete Face fails after rebuild, changes to face in another body

All

I have a delete-face feature that fails when I do a ctrl-Q rebuild. One of the selected faces switches to a face in another solid body, which of course the delete-face feature cannot handle. The part starts with, among other things, a body with a cylindrical face. I spilt that body, then try to delete a reminant of the cyclindrical face in one solid body. The rebuild changes the selection to a remnant of that same cylindircal face that is part of the other solid body.

Anyone seen this? I am hoping that a service pack later than 2010 sp2.1 has this fixed.

Thanks

Dwight

SolidworksParts And Features