[PHP] gd for php5 under RH ES4

I am trying to use the php gd library (for imagecreate, etc) with php5 under Red Hat ES4. I tried installing php-gd via webmin (which in turn, I see, uses up2date), but get the following error in the apache error log when restarting: PHP Warning: PHP Startup: Unable to load dynamic library '/

[PHP] Memory

I'm running out of memory even though I upped it to "memory_limit = 500M" in php.ini. Error messages and script are below. Thanks in advance for any tips. $ php -c /usr/local/php5/lib/php.ini createPseudoIDs.php > crosswalk.txt php(780) malloc: *** vm_allocate(size=1069056) failed (error code=3)