block delete method not working properly

I'm using Acad 2002. I'm iterating through the blocks collection. I perform
a selection set using group code (2) and the group value of (block name).
The selection set comes back empty. I perform objBlock.delete and I get an
error -2145386239 Object is referenced. So I'm assuming that the block is
being referenced by something else in the drawing, which is fine. However,
if I run the purge command and expand the blocks category, I see a list of
all the blocks that I tried to delete/purge in my routine but had received
an error saying the blocks were referenced. Using the purge dialog, I'm able
to delete them without the reference error. Something funny is going on.

Any feed back would be helpful. I know I can use the command line and
run -purge with the correct parameters but I'm hoping I can get some
clarification on why vba isn't deleting some of the block definitions. FYI -
there are some blocks that do get deleted in the routine.

Thanks,
Brent

 

Sounds like the block in question is nested within another block.