I have it typed out in a Word Doc file. I just cut and paste and go. No problems there.
If it's not accepting your password, you could've added a space at the end by accident, or there could be a character that's wrong.
Also, try cutting the password instead of copying it. Then just ctrl+z in the text file so it comes back.
Thank you! I will try that next time I need to sign it.
Another thing that just occurred to me is that it might be your browser. I have trouble logging in using Firefox every time. The only problems I've encountered when using Chrome were my own errors.