Menu/Navigation Bar Error

On my forums, some of the icons on the menu/nav bar are acting up. My problem is that some of the icons only appear when you hover it's location or they don't appear at all. These example forums use the same icons in which I implemented into my forums and they are acting up there as well:

http://demo.nicetheme.com/forum?theme_id=172610
http://demo.nicetheme.com/forum?theme_id=166805

If you hover over the icon left of the 'portal' icon, you'll notice it only appears when you hover over it. When you are logged into the forum, the 'profile' button is completely gone. I assume this is an issue with the image hosting website. Are there any ways to make these icons appear as normal again?

Thanks in advance.

Hi, it would greatly help if you could please provide your forum URL.

I don't like to necro post but this is an unsolved topic, could you solve it? 'Cause I also want to know the answer

I checked the skins that are in the first post. I believe it is an issue with the skins, becuase it did it when I reviewed them on my forum.