Some images are cached after flush but then stop caching.

When I flush the cache and then go to a page with images on them, some of them load, but then when I go to another page, none of them load. After the image hits a halting point, none of the images in that preset load until I flush the cache again, and then the problem is the same.

I have been researching this for hours. It works fine on my localhost and everything loads great. I am on a cloud server, I put my permissions to 777 on /files and /temp. I looked in temp for some "lock" file or something... someone suggested it. My memory level is set at like 128MB so I don't think it is lack of memory, but it seams like it. Because It caches fine for pages with not a lot of images. I tried deleting .htaccess, I tried fiddling with permissions... I am lost. Please Help.