Sorry to hear about the issues you've had posting. The pop-up box and other issues with pasting is generally a problem when using Internet Explorer, so if you can use another browser to access the forum, you shouldn't have these issues. If you prefer to use Internet Explorer, there's a detailed post on the forum, here, about what you can do to (partially) get rid of the pop-up box. Let me know if that helps!
Regarding the issues you, and other users, have had with losing posts, this is something we're investigating further. Thanks for the details you've already provided. Any additional details, such as which device (eg desktop pc/apple mac/tablet etc) browser, and browser version you are using, and when this occurs (eg after hitting the 'Post' button/after editing a post, etc) would be really helpful to us in troubleshooting. I've created a new topic, here, where you can post details, or feel free to send me a message.