Thank you !!
As I wrote, I have a blank pdf (size is only 1700 bytes). 
>From the log (attached below), it's a problem with fonts :
there is a whole page of 

simpleslides    : loading default font setup
define font | font with name unknown is not found
define font | unknown font unknown, loading aborted
define font | unable to define unknown as \*24ptsstfss*

I'm reading messages about beta and font generation, maybe it's related.

Best
Amaël

Le jeudi 07 mai 2009 à 13:14 +0200, Taco Hoekwater a écrit :
> 
> Amaël Broustet wrote:
> > Ok I thought i didn't need to do 
> > luatools --generate 
> > I run it and after that I got the same error with markIV that with
> > markII :
> 
> After looking at your input, this is expected. The argument to
> 'size' is a dimension, so it should be followed by 'pt':
> 
>   \usemodule[simpleslides][style=BigNumber,font=Helvetica,size=24pt]
> 
> Best wishes,
> Taco
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