[Plugin: WP Super Cache] This plugin slows mysite

<!– Dynamic page generated in 57.190 seconds. –>
<!– Cached page generated by WP-Super-Cache on 2010-05-25 13:33:12 –>

Something bad happening, pages load too slow for the first time (probably, when cache is being generated). On the second it flys.

Used 2 plugins
wp-super-cache (http://wordpress.org/extend/plugins/wp-super-cache/)
wp-file-cache (http://wordpress.org/extend/plugins/wp-file-cache/)

If I switch of wp-super-cache site loads straight.

Any idea, how to fix this?

Thanks.