Level texture issue

[DemoMan2]

Hi Guys,
I have an old map that I am working on that came up with an interesting problem this week. It seems that one or more textures are not visible when the map is run in UDK (I.e. It shows the "undefined" texture default) but they show up fine in the editor and even when I use PIE modes. Any ideas what could be wrong?

[JessieG]

Are they only disappearing from a cooked game?

[DemoMan2]

Are they only disappearing from a cooked game?

From both the cooked game (Using Frontend) and from running UDK in non editor mode. They only show up in the editor for some strange reason.