I have a serious problem here, every time I publish and update a page/post it displays a white blank page.. here I don't know how to fix it.. is there anyone that can help me? Thanks :)
It's likely a plugin. Disable them, and see if that fixes it. If it does, enable one by one, until you find the culprit.
If it's not a plugin (and even if it is), you can try to increase the memory allocated for PHP. Add this to your config.php:
You can read more about the memory limit here: http://codex.wordpress.org/Editing_wp-config.php#Increasing_memory_allocated_to_PHP