In some circumstances IE may not show the icons on buttons. This is due to the font not downloading to the browser.

This can be solved by allowing fonts to download.

First, click the gear icon in the browser

Next, select Internet Options

On the Internet Options dialog, click the Security tab.

If unicentric.com is set up as a trusted site, select "Trusted sites", else select "Internet"

Click the Custom level button

Scroll down in the settings list, and enable font download

Click OK, and OK again. Close all browsers, and re-open the site. The icons should now show.