After adding lots and lots of one-line text strings to a JeditorPane
by doing getDocument, appending to the document, and doing setDocument,
when the amount of data in the Pane becomes moderately large (200kB?)
Then scrolling it causes the background to change from white to grey,
and selecting text (highlighting it) whie the JEditorPane has been
setEditable(false), causes the text to become scrambled.