Why this code doesn't run?

"Jan Grzdyl" <[email protected]> Fri, 26 Oct 2007 23:55:43 +0200
Newsgroups gmane.comp.web.smil
Message-ID <[email protected]>
Hello,

I am newbie in smil subject and I have some question for you:
Why this code:

<smil xmlns="http://www.w3.org/2000/SMIL20/CR/Language">
<body>
<par>
<img src="./myimage.jpg" end="wallclock(21:00)" dur="5s"/>
</par>
</body>
</smil>

doesn't work? It seems that problem is connected with wallhack function.
Every time I want to use wallclock then realplayer throws:

General error has occured.

Maybe I have some old version of realplayer - this is 10.5. But it seems
that it is newest. I use winxp without any servicepack. Maybe there is a
problem?

opexoc