Bug in pretty ref

[Vincent VAQUIN]

Hello,
I'am using lyx.1.1.5 with Linux, and I have a bug when I want to insert,
in cross reference, pretty ref.
I can insert it, but when I try to compile, lyx say : error, and I have
this message :
"paragraph ended before \@prettyref was complete. I suspect you'have
forgotten a '}'."
On the tex source document, I have this :
blabla \prettyref{r=E9f=E9rence} blabla
What's wrong ?

-- 
Vincent