上传过多图片时的PHP白页

I got a problem regarding a form I have. It's an image upload form which you can upload images with with a file input. When I try to upload 21 images it doesn't work but when I put 17 images in it it works. The 21 images gives a white page and it uploads images till the 17-18 (it differences).

Now I checked it out and I think, but I'm not sure, it has to do with the internet speed. If I try it on a slow internet speed it gets canceled but else the images get through.

I changed my .htaccess with the following fields:

php_value post_max_size 1000M
php_value upload_max_filesize 1000M
php_value memory_limit 1000M
php_value max_file_uploads 100
php_value max_input_time 600
php_value max_execution_time 600

Has it to do with the execution or input time? The slow speed actually can actually process for 15 minutes before the white page shows. Or am I forgetting php values I need to set?

I would suggest adding the following to the top of the upload script to see exactly what is causing the failure.

error_reporting(E_ERROR | E_CORE_ERROR | E_COMPILE_ERROR);
ini_set('display_errors', '81');

This "should" show the exact PHP error that is occurring, which will help you determine how to correct it.

I would also MAKE SURE your PHP changes are actually taking effect by checking the result in phpinfo(); Could be that the Apache HTACCESS changes are not overriding the php.ini settings?