Cyrillic letters in math mode

[Roman Belenov]

Hello,

I've  just  configured  fpTeX,  so  everything  works.  But when using
cyrillic letters in math mode I get warnings like

LaTeX Warning: Command \cyrm invalid in math mode on input line 1345.

and  no  cyrillic  letters in output. I had the same problem in MikTeX
1.20b  (with  native  or teTeX texmf tree, the results were the same).
But at home in teTeX 0.9 (I don't remeber the exact date, I downloaded
it  this  spring)  I have no warnings and correct output with cyrillic
letters.  I  didn't move teTeX 1.0 distribution to home yet so I can't
tell if teTeX 1.0 have this problem.

Does  anybody  know  what happens ?

Best regards,
 Roman                          mailto:roman@nstl.nnov.ru