Smush server was unable to access images from your site.

Hello,
I get this message:

Smush server was unable to access images from your site.

... I had previously tried to send a smush request, which actually resulted in a crash of my site

"Allowed memory size of 67108864 bytes exhausted"

Now its not letting me re-smush the images.

Also, I would rather that it didnt kill the site too.

thanks!