Lyx does not display all math symbols

[Benoit Pelletier]

Hello,

I recently installed lyx-1.1.5fix1 on my Mandrake 7.1 machine using the
rpm provided on the lyx home page.

Some of the math symbols do not show on the lyx window; the integral and
the sum (I did not try them all) don't show for sure.

Any idea of what could be wrong?
Thanks,

Benoit Pelletier