Out of Memory when Uploading an Image

This isn’t a WordPress problem. There’s no telling on a shared environment what the culprit might be. You probably don’t have access to your php.ini config, nor do we know how many websites your hosting company has jammed on your server.

The very nature of a shared server is that each client shares the resources of that one server. If one website is using massive amounts of resources while you’re trying to upload your image, that would certainly affect it.

The only real fix to this is getting onto a more controllable environment. I gave up on shared hosting a long time ago and went with a cloud server from Rackspace. I am in complete control and I don’t have to worry about other memory hogs on the same box.