I'm new to Zezphoto. My image rotate is greyed out, and I understand from the troubleshooting guide that this means my GD may not have that capability. I contacted my host, and they say that it does, I have the latest GD version. Can someone suggest next steps?

Tell your host that your version of GD is not properly configured with the imagerotate function.

Is there a way to help them understand how to properly configure it with imagerotate?

If they do not know this, what kind of service are they providing you anyway? No, I do not know how to configure these things. That I leave to my service provider. That is where the expertise should reside.

The imagerotate() function was kept out of the GD library that comes with Ubuntu and Debian and perhaps others. Perhaps that is your (provider's) problem. Regardless, there is a replacement plugin to provide the same functionality, though it is unsupported. If nothing else, you could try it. http://www.zenphoto.org/2010/03/image_rotate_gd/