strange \v!on

[Hans van der Meer <hansm@science.uva.nl>]

Encountered something strange setting up the parameters of framed.

This runs normal: 	\setupframed[frame=off,strut=\v!no, ...

This gives an error:	\setupframed[frame=\v!off,strut=\v!no, ...

The same happens with \v!on as parameter.
The difference is "off" vs. "\v!off" (of course running within  
\unprotect .. \protect pair).
It seems to go wrong at the "frame" parameter only, because for  
example strut accepts \v!no.
Is there perhaps a clash with another macro?

I get this in the console (TeXShop):

! Missing \endcsname inserted.
<to be read again>
                    \let
\dobuildtextaccent #1#2->{\let
                                \char \normalaccent #1\let \char  
\normalchar #2}

\dohandleaccent ...acterencoding #1\endcsname {#2}
                                                   \fi \fi \fi
\@@oiframe ->\v !
                  on
<argument> t\@@frame@@ \framedparameter \c!frame
                                                  \framedparameter \c! 
topframe
\getvalue #1->\csname #1
                         \endcsname
...
l.44 \stoptable
                }{first table}
?
Process aborted


yours sincerely,
dr. H. van der Meer