Have you read any of what I said? Its not a "bad" wifi file but a mismatched one. As the system modules (wifi) are located in the kernel, when you have a mismatched kernel wifi will fail to function properly for some people. Our phones are very forward compatible but fail to be very backwards compatible as slight changes are made to the source with each version. Especially the kernel with 2.2.2That's what I would try doing but I've tried so I think its a bad wifi file in the zip....
Anyways goto the Market and download MiiLocker. They have tons of unlock screens. Although I would uninstall WidgetLocker before you install MiiLocker otherwise you could run into complications. If you have any other questions you can private message me for info.