If you attempt to log in with a locked account, you are correctly prevented from logging in.
However, you land on the Project Groups page, but it has no header, just the text "Account Locked" in black. It should send you back to the login page with an error message.
In addition there is a stack trace in the logs/on the console:
INFO | jvm 1 | 2006/12/25 21:45:50 | 2006-12-25 21:45:50,828 [SocketListener0-0] WARN OgnlUtil - Caught OgnlException while setting property 'infoMessage' on type 'com.opensymphony.webwork.dispatcher.ServletActionRedirectResult'.
INFO | jvm 1 | 2006/12/25 21:45:50 | ognl.NoSuchPropertyException: com.opensymphony.webwork.dispatcher.ServletActionRedirectResult.infoMessage
INFO | jvm 1 | 2006/12/25 21:45:50 | at ognl.ObjectPropertyAccessor.setProperty(ObjectPropertyAccessor.java:133)