itemize[loose]

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

When typesetting an enumeration with a specified item text I  
encountered an error with the combination of [loose] with \sym{} and  
\mar{}.
The hope was that "loose" will allow underfull filling of the lines  
without complaint (I don't like TeX complaining)

An example follows:
\starttext
\setupitemize[loose]
\startitemize
\sym {xyz} 12345
\stopitemize
\stoptext

Error message:
! Undefined control sequence.
<argument> \optimizeitemsfalse

\p!compareprocessaction ...commalistelement {#3}#2
                                                   \expandafter  
\quitcommalis...
etc.

Is this expected behaviour? The manual does not give me an idea about  
that.

yours sincerely,
dr. H. van der Meer