When a new LDAP user subscribes to the system a rhodecode user is created with the same username. The problem is that the user won't be able to be activated while it has "@" (at sign) in its uid.
message: Username may only contain alphanumeric characters underscores, periods or dashes and must begin with alphanumeric character or underscore
The solution would be to replace "@" for "-" at the moment of rhodecode's user creation, and for such, an extra field to store the original uid would be created. By the way, gitorious does that.
tested version: 1.7.1