Rename attachment when saving from text

[joesmo74]

I know how to save an attachment from a text, but for a while my phone (Glaaxy S2) would let me name the file when I saved it. Now, whenever I try to save a file from a text message, it wants to automatically save as "inagejpeg_2.jpg". The problem is that this automatically overwrites the previous file that was saved with the same name. How do I change the settings so that I can name the attachment when I download it, not after I download it? Thanks