Error in wp-includes/SimplePie/Parser.php

Hi,
I am developing a new site with WordPress Hebrew. Within the administrator interface, I received a message stating:

Fatal error: Allowed memory size of 41943040 bytes exhausted (tried to allocate 122880 bytes) in /usr/home/lllisrael1/public_html/lllisrael.org.il/wordpress/wp-includes/SimplePie/Parser.php on line 195

Does anyone know how to resolve this error?

Thanks.

Devorah