xwatermark allpages does not work on Ubuntu

[Václav Haisman]

I have a document that typesets fine with MikTeX on Windows. I have tried the same source on Ubuntu but I am getting an error:

~~~~
! Package xwatermark Error: No page specifier for watermark:
||{\fontspec {Georgia}Confidential.}||.

See the xwatermark package documentation for explanation.
Type H <return> for immediate help.
~~~~

The xwatermark version appears to be 1.5.2a, February 2012.

Is this a known problem? Are there any workarounds?

Reduced complete test case:

~~~~
\documentclass[]{article}
\usepackage{xcolor}
\usepackage[printwatermark]{xwatermark}

\newwatermark[allpages,textcolor=gray!35,textangle=60]{{Confidential.}}

\title{Title}
\author{Vaclav Zeman}
\date{2013-05-31}

\begin{document}
\maketitle
\end{document}
~~~~