JQuery Issue

Module has a slight issue with jQuery 1.3, as the [@ selector actually doesn't work anymore. This causes the code to hide all the payment options, instead of just the free one. Even in jQuery 1.2 this was deprecated, so this patch should work for anyone using jQuery 1.2 or 1.3, which I believe Drupal 6 comes with 1.2. Nearly useless for 1.2 users, but nice to have anyway, no real reason to support super old jQuery (maybe even add a dependency on the jQuery Update Module or something, since it's a nice module to have anyway).