[NTG-context] buff_gobble error MathML

Hi friends, we need to run MathML inside \sym (see below). Is there a way to solve the error "! Argument of \buff_gobble has an extra }." Thanks, Steffen ------- \usemodule[mathml] \starttext \setupitemize[1][broad][margin=no,distance=0em,width=0em,align=stretch] \startitemize[1][width=5cm] \sym{\startbuffer http://www.w3.org/1998/Math/MathML"> <msub xmlns="http://www.w3.org/1998/Math/MathML"> <mrow> <mi>g</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo xmlns="http://www.w3.org/1998/Math/MathML">,</mo> <mi xmlns="http://www.w3.org/1998/Math/MathML"> </mi> <msub xmlns="http://www.w3.org/1998/Math/MathML"> <mrow> <mi>g</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> \stopbuffer\processxmlbuffer}Vektor \stopitemize \stoptext