Using version 1.7, I get Parse error: syntax error, unexpected T_STRING in .../wp-content/plugins/gravityforms/form_display.php on line 559. Even on the homepage where there is no gravity form included. It was working all day yesterday, and then suddenly out of no-where this error appeared, blocking the display of the rest of the site.
I was using WP Super Cache, but I've turned that off and cleared the cache, but that didn't change anything. Deactivating gravity forms removes the error.