lots of data starting with rss_* in wp_option table make memory exceed error.

I am using eaccelerator & wp-cache.
for several days, I have memory error ,’wp-include/cache.php on line 4′

I deactivated all of plugins and checked my code.
And then, I found that that is caused by bunch of rss_* data.

It loads all of wp_options’s data with cache.php. So I must delete datat starting with rss_* in wp_options frequently.

This is so critaical problem.
how can I delete rss_* with automatic or not use rss_*?