Using dashes instead of underscores maybe?

Try cutting and pasting the permalink URL, rather than manually typing in a URL. (Would reveal what you might be missing).

:D

Thanks for the reply. Maybe in my ignorance I'm missing a big step....where would I cut and paste it from? I'm creating the link by typing it into the URL window....right?

when you see the post in the backoffice, you'll see in the rightbottomcorner a 'permalink'..
just copy and paste the url it generates...

Thank you!