If you deleted media from your DVD Studio Pro project it is important to also remove all connections to it otherwise it can disrupt your project.
DVD authoring is about maintaining perfect connections between the format of the disc and the media assets that have been added to it. When something is severed there can be problems for everything else in the authoring process. This is why when you are removing certain assets or items from your DVD authoring project you must change all the connections as well.
There are times when you like to use the general format that you have created for a DVD but just remove some media. This may be because the total size of the DVD project is exceeding 4.7 GB, or simply because it is not appropriate for the specific use. If you remove the asset, or if the saved asset on your storage device cannot be found, then this will disrupt every track for which the asset is being used. This will create an overall problem with the DVD and will prevent it from being burned in DVD Studio Pro. In this way it is not just good enough to sever the connections to the menus that are linked to the tracks you have removed the media for, but instead you must all together delete any track or menu that is referencing deleted or unavailable media assets. If there is any type of connection to the deleted assets, even if it is from a menu or track that has been disconnected from the main DVD flow, it must be deleted otherwise DVD Studio Pro will cancel any burn attempts.
The reason the project will not work is that DVD Studio Pro provides this as a safety measure so you do not burn a DVD that is linking to media that was offline. It gives you this warning so you can reconnect the media to these places, just as you would in your Final Cut Pro editing project. To ensure that your disc is going to work correctly after the alterations you have made make sure that all menus and tracks that were using those assets have been removed completely. Make sure that all buttons linking to those tracks have also been altered or removed. The final thing is to test out your DVD with the simulate function to make sure everything is running how you would want it to.
The burning log will also tell you additional information about what is going on with your DVD while it is being created. This is an important thing to monitor just to make sure you do not have blank connection, dummy buttons, or missing tracks. Burning a DVD takes work, so it is important to double check it and remove any references to video, photos, or audio that you do not want on your disc anymore.