I seem to be having a very odd problem with my iPhone project in XCode4.
By accident, I seem to have dragged a new group I created out of my main project group:
When I try to move the group back into the project group, XCode crashes. When I try to delete the group by dragging it to the trash can, no such luck either. Is this because it's an iPhone project, and I somehow have messed up the entire directory of groups?
Solved- I hit the delete button with the group selected, and clicked "Continue" when presented with the error dialogue, which ended up removing the group.