Do I need zend_optimizer?

[OM2]

My server came to a halt.
My tech support had it back up qucikly.
They said the problem was that I had APC and zend_optimizer - they told me that I couldnt have both.

I know I need APC for an upload progress bar.

But: zend_optimizer...?
What is this?

I've been told by my tech support that APC and zend_optimizer: you can't have at the same time.

They've recommneded I keep APC.

Any comments about the above would be appreciated.

Thanks.


OM