Seems the GD image library can't handle all the photo uploads on our site so the server's been throwing memory limit errors. I upped memory to 128 and that fixed things for a while until the error started surfacing again. I suspect that the functions aren't releasing the memory upon completion of the process, thus accumulating until it trips the memory limit error. Can anyone confirm that it does this, or not?
GD functions are very memory intensive. Make sure you're exerting some level of control over your user input so you can't save yourself these headaches.. I recommend using the file_size_limit parameter to keep large files out. By default that is set to the value of your PHP.ini upload_max_filesize, but it can certainly be lower if you need it to be.