Changing default context with Jahia 4.1.0

I am currently running Jahia 4.1.0_01 and have changed the default 
context - in this case to 'npbs' so the url will look something like:

http://localhost:8080/npbs/pid/2

When in edit mode, the admin menu links 'My Settings' to
http://npbs/engineName/mysettings/op/edit/pid/2?matrix=1122875187315

rather than to 
http://localhost:8080/npbs/engineName/mysettings/op/edit/pid/2?matrix=1122875187315

this also occurs for most links on the default homepage e.g.
Add Text
Add a portlet
Update image etc.

The only links that seem to work are
Administration
Page properties
Metadata
Site settings


Has anyone else had this problem?