I have frequently found that I am unable to copy text from documents in read mode. The Copy option is available in the menu, but does not seem to work. When you attempt to paste - the previous clipboard contents are there.
This caused a great problem when I pasted 3000+ documents instead of the type-ahead text I was expecting to paste.
Copying from docuements in Edit mode is not effected.
This happens mostly in my R8 mailfile