nested itemizations: missing vertical space

[Eckhart Guth�hrlein]

Test file:

\starttext
    \startitemize
       \item ?
       \item ??
          \dorecurse{20}{bla bla bla}
          \startitemize
             \item one
             \item two
             \item three
          \stopitemize
          \dorecurse{20}{bla bla bla}
       \item ???
    \stopitemize
\stoptext

There is no vertical space after the end of the inner itemization. 
Furthermore, the 'joinedup' parameter has no effect.
?

Eckhart