memory card only reads 32 megbytes free?!?

i was aranging my memory card and what i do is save the files in to my computer and delete them from my memory card for future projects as i cleared it up abit it wont let me drag and drop files in to it?? my computer says not enough space ?? for some reason the memory card reduced its capacity i dont know whats going on

My guess: You marked the files for deletion without emptying the trash, so the files are still taking up space on the card in the trashes folder.