InsetLayout CharStyle:MenuItem

[Max Bian]

If I have "InsetLayout CharStyle:MenuItem", it works. If I have 
"InsetLayout CharStyle:Menu_Item" in a layout module, LyX displays it as 
a red box. I like the latter since it displays a space in the Edit->Text 
Style menu. Not sure why it would be red though.

Any idea? I am using LyX 1.6 on Windows.
Thanks.

Max