Roadmap plugin on Firefox generates annoiying attachments while copy/paste items.

Bug has been noticed only on Firefox 34.0

Steps to reproduce:
1. Create a page with inserted Roadmap chart.
2. Copy random item (text, macro, picture).
3. Edit the page and paste the item.
4. In result I get attached .png file with roadmap chart.

It open an attachment dialog and attach the picture of roadmap chart as .PNG file.