Why doesn't Nemo preview thumbnails?

Nemo makes previews only for files less than one MB by default. You can change this from its preferences:

The solution below works for 32 and 64 bit systems (tested on cinnamon 17):

In your home directory remove the .thumbnails subdirectory:

rm ~/.thumbnails

Set a new link for the cache folder:

cd ~
ln -s .cache/thumbnails .thumbnails

To fully flush everything out consistantly, I ended up having to use a small script to clear out all the cached files and reset the symbolic link to the cache folder. This worked for both nemo and nautalus. I made sure to shut down the file manager at the end of the script too. Then when I next opened the folder, all the thumbnails reloaded. Be sure the file size for thumbnails is set high enough. I have a couple MP3 files over 10meg so I have my preview level set to 100meg.

#!/bin/bash

find ~/.cache/thumbnails/ -type f -exec rm {} \;
rm -rf ~/.thumbnails
ln -s ~/.cache/thumbnails ~/.thumbnails

killall nautilus    # in case you are using nautilus
killall nemo        # in case you are using nemo