OK Try this... go into your mail select (put a check mark next to) more than one document and drag them to the trash. Now click once on another document and hit forward. If you put check marks next to other documents in the inbox and hit forward they all will show up. It is clear that draging them to the trash doesn't clear the selection.
So why did I post this if I know the answer? Thought it would be good for the PAQ and I submitted it to Lotus and I will update it when Lotus fixes the bug.
Points awarded for the best use of this undocumented feature!