[PyMOL] Selection/remove bug?

[Jim R. <rem...@mo...>]

Dear All:

One of our crystals contains a dimer in the asymmetric unit, with chains 
labeled A and B.
If I want to display chain b, I can first select chain a and remove the 
atoms, using the commands:

select a, chain a
( (a) action menu: remove atoms)
Result: atoms removed

However, if after beginning anew or otherwise, I want to display chain 
a, the same commands fail.

select b, chain b
( (b) action menu: remove atoms)

Result:
Selector-Error: Malformed selection.
( b )<--

Any advice would be appreciated!

Thanks, Jim