Given that WordPress allows you to move the wp-content directory, you can't hardcode it's location. There are all sorts of broken issues like not being able to preview forms because of this.
Affected constants:
GRAVITY_MANAGER_URL, use WP_PLUGIN_URL
Affected files:
- downloads.php
- preview.php
- print-entry.php
- select-columns.php
If you need access to WordPress functions, or need to find dynamic paths like wp-content, I wrote some code that allows you to do this:
https://gist.github.com/1241505