Edit: Thinking more about this.... It's possible that for some reason, the users were seeing the "greyed out" homepage behind the news flash box, and not the newsflash window. I don't know why the newsflash window would not have been registering right in the middle of their screen. I've asked them for a clarification, plus their browser/device info, and will report back.
Bet you thought I'd forgotten about you.
Couple of users are reporting that a "black screen" appeared 9/19-9/20 when they tried to view our site. I thought it was a blip, but then one of them reported that it was the NEWS FLASH pop-up that was black, as they were able to scroll up and click the X to close it and continue.
I looked at the html of our newsflash, and it's very straightforward. Nothing odd or fancy. It simply reminds people to update their profile.
I've tried to recreate on iphone, IE and Chrome to no avail. Cleared my cookies, signed in under different account, etc. Doesn't goof up.