I have a very odd permissioning issue going on.

I have three environments.  A development, testing, and production environment.

After last porting a solution from dev to testing, users with a specific custom security role no longer had access to view Accounts of any kind.  When looking at a list of accounts, all the user sees is a message stating "You do not have permission to access these records.  Please contact your Dynamics CRM Administrator."

This failure does not occur with this security role in my dev or production environments.  The security role grants organization-wide read privileges on Accounts.

What could be the problem?