Okay,

So i ran a script called /scripts/installzendopt hoping it would install Zend. However all it did was down my site and all other sites.

Any idea's ??

what do u get when u go to the sites? have u tried to restart httpd?

I'd recommend installing Zend manually. Like JeeWhizz said, try to restart httpd

service httpd restart

I installed zend sepearateyl and it worked fine

Same here. Never used the Install script. Except that I had to restart httpd manually sometimes.

run the script and when it asks what version of php ( assuming you are running php 4.3.1 ) select the manual select option. Then select 4.3.0 and complete the install.