I am using the follwing (extracted) typescript lines for math in the lucida fonts:

\starttypescript [luc]
    \definetypeface [luc][mm][math][lucidayy][default][encoding=texnansi]
    \definetypeface [luc][mm][bfmath][lucidayy][default][encoding=texnansi]
\stoptypescript

\starttypescript [math] [lucidayy] [default]
    \definebodyfont [default] [mm]
      [mr=MathRoman mo 1, mi=MathItalic mo 1, ....]
\stoptypescript

\starttypescript [bfmath] [lucidayy] [default]
    \definebodyfont [default] [mm]
      [mrbf=MathRomanBold mo 1, mibf=MathItalicBold mo 1, ....]
\stoptypescript

\starttypescript [math] [lucidayy] [name]
  \definefontsynonym [MathRoman]         [LucidaBright]
  \definefontsynonym [MathItalic]        [LucidaNewMath-AltItalic]
\stoptypescript

\starttypescript [math] [lucidayy] [texnansi,ec,8r]
  \definefontsynonym [LucidaBright]                [hlhr8y]   [encoding=texnansi]
  \definefontsynonym [LucidaNewMath-AltItalic]     [hlcrima]
\stoptypescript

\starttypescript [bfmath] [lucidayy] [name]
  \definefontsynonym [MathRomanBold]     [LucidaBright-Demi]
  \definefontsynonym [MathItalicBold]    [LucidaNewMath-AltDemiItalic]
\stoptypescript

\starttypescript [bfmath] [lucidayy] [texnansi,ec,8r]
  \definefontsynonym [LucidaBright-Demi]           [hlhb8y]   [encoding=texnansi]
  \definefontsynonym [LucidaNewMath-AltDemiItalic] [hlcdima]
\stoptypescript

Typesetting:
\starttext
\usetypescript[luc][texnansi]\setupbodyfont[luc,10pt]\lucidatrue
{$\sqrt{a^2 + b^2} = c + \mf\sin{}x\quad {\ma NZRC}$}\crlf
\stoptext
 Gives me for the variables neatly LucidaNewMath-AltItalic.

But typesetting
\starttext
\usetypescript[luc][texnansi]\setupbodyfont[luc,10pt]\lucidatrue
{$\bfmath\sqrt{a^2 + b^2} = c + \mf\sin{}x\quad {\ma NZRC}$}\crlf
\stoptext
Gives me LucidaBright-Demi instead of LucidaNewMath-AltDemiItalic.
Everything else however (even the blackletters from ma) are in the correct bold math font.
The font must be present, because substituting MathItalicBold for MathItalic in the [math] script proves that.

It seems that mibf has not been substituted, but instead used the mr typeface.
Could this be a flaw in the (bold)math handling? For example a wrong fam chosen in the font switch?
It seems weird that everything behaves neat except for the bold math italic.

Hans van der Meer