I deleted 1.5 and uploaded 1.6 Beta 3. When I activated the plugin I got this error:
Warning: opendir(/home/zachdoty/public_html/wp-content/uploads/gravity_forms/) [function.opendir]: failed to open dir: No such file or directory in /home/zachdoty/public_html/wp-content/plugins/gravityforms/common.php on line 65