low memory hack

freememory

Whith cheap web hosting, php memory is limited to 32MB.
Then, when loading a large-sized image, ZenPhoto fail to create thumbnail/cache.
In this failure case, my proposal is just to show the full original image as a thumbnail, instead of nothing. In other words, let the browser resize the image client-side.
This is a hack, but it should be easier to implement and to use than ImageMagic.

sbillard

When the resizing fails, the error aborts the script, so there is not much we can do. PHP 5 might be able to trap the abort, but PHP 4 cannot.

acrylian

Besides that letting the browser scale down big images is bad webdesign practice since forever... I would think the best fix is not to upload images bigger than your server can handle.