A project is reloaded any time you make a change to a file in the project (modify a requirement document, etc...) or the project structure itself (add or remove a link, etc...). When the project is opened, some information is retained about the state of the project, so not all of the documents are reloaded. If a document has changed or needs to be reanylzed, NIRG will attempt to do so (after prompting).
Sometimes this process can be very time consuming (if you have very large requirements documents or thousands of VIs to parse for example), so we try to minimize when a load is done. I am not sure why the Rules Check pane is not getting properly refreshed, but its something that we will look into for a future version. If you do see something that you would expect to be updated, but isn't, occasionally NIRG doesn't notice that a file has changed or something has been modified. Certain types do not provide information about when they are updated, so we don't know to reload it. Forcing NIRG to reload all documents is a way to guarantee everything is up to date.
Allen P.
NI