[pdftex] ! Math formula deleted: Insufficient symbol fonts.

[G. D. Brettschneider]

What can be wrong with my font (or pdfTeX) installation, if

a) font map, tfm and pfb files are taken from a teTeX installation which 
runs properly,

b) pdfeinitex, dumping on plain.tex, reports sucessful preloading of all 
50 standard Computer Modern fonts,

c) pdfetex, typesetting a file which just contains "\tensy @\end", 
produces a pdf showing an aleph letter,

d) but fails on "$\aleph $\end" by saying:
! Math formula deleted: Insufficient symbol fonts.
l.1 $\aleph $
             \end
? h
Sorry, but I can't typeset math unless \textfont 2
and \scriptfont 2 and \scriptscriptfont 2 have all
the \fontdimen values needed in math symbol fonts.

?

Thank you for any help,

Gerolf