Help me to optimize "W3 TC" plugin for WP

[David Dobo]

After 2~3 days, installing of W3 Total Cache plugin I, in my Admin page have massage:
{ Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 491520 bytes) in /home/nsige/public_html/wp-includes/class-simplepie.php on line 1486 }

Very usefull and interesting instruction of resolving this problem I find in this site:
http://perishablepress.com/press/2008/02...-cachephp/

I opened php.ini and .htaccess files and put it in the directory "wp-includes". But I have result only changing the in end of "Fatal error" massage, - number of line (1486 >> 5410):

I have now new massage:
Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 1966080 bytes) in /home/nsige/public_html/wp-includes/class-simplepie.php on line 5410

+ I was informed form hoster that PHP Configuration > memory_limit 24M is unreal and I must open own php.ini in directori to take full memory resources (but <200M). I open php.ini (+ .htaccess in directory wp-includes) and insert there 128M

I think allso, that my Data base is full or not ;( (with red collor in cPanel)...