App crashes when loading images from the server

Hello Guyz,

I am developing an App that loads different images from the server. the thing that happens, is whenever I load an image, it reserve a big chunk of memory, and after loading like 20 images and even if I am not using these images anymore(no references are pointing to them) the garbage collector do nothing,so it crashes because the memory is full. Now I searched and I found that Unity3d has a bug, it doesn't clean the memory used to convert the image to texture2d. is there a way to clean this memory? is there a better way to load images from a server other than WWW(URL) so it wont use all that memory?