Theme makes tab title disappear

[Jorlem]

I just switched over from Firefox, and I would like to continue using the theme I had been using with it. This theme changes the appearance to that of Firefox 3. However, in Palemoon, it is making the on-tab title for the active tab disappear. Everything else appears to be working as it should, save this. I am perfectly willing to dig into the theme and make changes to get it to work, except I don't know what to change. Any advice?

Edit:

While holding my laptop at an angle, I noticed that the tab title for the active tab isn't technically vanishing, but is instead turning white. As the selected tab is a very pale gray, it appeared as if it was vanishing, when it was actually camouflaged. So, to amend my original request for help, does anyone know what I should do to make the selected tab's title from changing color?