Problem uploading product images

[takumi]

Hello prestashop,

i've a problem uploading product images in the backoffice.
When I upload images in the Back Office it gives me a blank screen.
On my webserver the image is stored in the /tmp folder but isn't created in the /p folder, as a result I see no images for products, there are missing. It only happens when images are larger then 20 - 30Kb. When uploading tiny images, there's no problem. Larger files like 800kb won't work. There are stored in the /tmp folder, but nothing happens after that.

It seems prestashop takes the upload into the temp folder, but doesn't regenerate them to the dessignated /p (product images) folder.

I already read any thread on this forum containing this problem. My img folders have 777 file permission.

These are my versions
Prestashop 1.2.5
Apache version 2.0.63
PHP version 5.2.11
MySQL version 5.0.85-community

Can anyone please help me out? I cannot fix it and it's really frustrating, because i cannot find the problem myself.

Thank you very much.