I have a webview in my iPhone application, and I also have some html files inside my Resources folder. When my app loads, I load in a page from my resources into my webview.
Try loading OtherPage.html first. If you can't then it's not there, and you've missed some part of adding it to the project. If you can, then there may just be a typo in the link, or the baseURL could be incorrect, as stated by August. When I created an html file with images in it that were in the resource file, it worked fine just using