I see one of the bands is display table and the other is block

I not sure - is that an issue. Both are giving trouble

Actually they're both set to table. Change them to block

If Eric's suggestions don't do the trick, I'm wondering whether half the people have different settings for IE11. For example -

(a) In the IE 11 Internet Options, one can change the security level in the Security tab. The default setting is Medium-high for Internet and Medium-low for Local Intranet. If it is changed to High, and IE 11 is restarted at a viewport of less than 640px, the menu in the green bar below the picture doesn't work.

(b) In the General tab of the Internet Options, near the bottom right there is an Accessibility button. In the box to which it leads one can choose 'Ignore colours specified on web pages'. If that option is chosen, the green bars disappear, but the menus still work at all viewports.

I would be inclined to request a screen-shot of what is seen on those monitors that fail to show the green bars. As Inger said, it isn't clear exactly what half the people can't see.

Frank

I'm with Frank On this one on my IiE 11 it asks me to allow blocked content when I sat yes displays ok

Great catch Frank. IE is such a pain

Byron needs to get on to one of the company IT reps and, since he is not allowed to enter their 'security vaults' himself, maybe together with someone who has the clearance, and then check a couple of PCs for their internet settings in IE - and the monitor settings that I have been banging on about.
If the settings for some reason have to be at a level that makes it impossible to see the navbar without scrolling, then the navbar would be better placed above the image, and the images (those main ones) should be made the same aspect ratio and size, possibly a bit smaller than what they are now.

Thanks guys

I think I have finally convinced them its on their end. Posting on a few different servers and it views fine seem to have helped!

Thanks for your assistance

Byron

Isn't IE scheduled to go out of support this year?

I have found no evidence to suggest that IE 11 has any date set for the end of its support by Microsoft.

Frank