Font name in LuaTeX's fontspec

Question

I have a document using fontspec which works fine with XeTeX, but a the Linux Libertine Initialis O font is not found when compiling with LuaTeX:

Here is a MWE reproducing the problem:

\documentclass{scrbook}

\usepackage{fontspec}
\usepackage{xunicode}
\defaultfontfeatures{Ligatures=TeX}
\setmainfont{Linux Libertine O}
\newfontfamily\lettrinefont{Linux Libertine Initials O}

\usepackage{blindtext}

\begin{document}

\blinddocument

\end{document}

With lualatex (TL2011), it returns:

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!
! fontspec error: "font-not-found"
! 
! The font "LinuxLibertineInitialsO" cannot be found.
! 
! See the fontspec documentation for further information.
! 
! For immediate help type H <return>.
!...............................................  

l.7 ...ly\lettrinefont{Linux Libertine Initials O}

Here is the font in fc-list:

Linux Libertine Initials O:style=Initials

My ~/.texlive2011/texmf-var/luatex-cache/generic/names/otfl-names.lua also contains an entry for this font:

  {
   ["familyname"]="Linux Libertine Initials O",
   ["filename"]={ "fxli.otf", false },
   ["fontname"]="LinLibertineIO",
   ["fullname"]="Linux Libertine Initials O",
   ["names"]={
    ["family"]="Linux Libertine Initials O",
    ["fullname"]="Linux Libertine Initials O",
    ["psname"]="LinLibertineIO",
    ["subfamily"]="Initials",
   },
   ["size"]={},
   ["slant"]=0,
   ["weight"]=400,
   ["width"]=5,
  },

Am I missing something?

Answer 1

Using the name as specified in the otfl-names.lua works:

\newfontfamily\lettrinefont{LinLibertineIO}

However, I don't know why it worked for other fonts without using this name, and how I'm supposed to guess this name from the output of fc-list...