Can't Edit Document Library form in SharePoint 2010

NOTE: I posted this about an hour ago but for some reason, it got deleted.

One of the features I looked most forward to working with in SharePoint 2010 is the ability to customize a list's add/edit forms in InfoPath. I created a very simple custom list and the ability to edit those forms was as easy as advertised. However, when I created a document library with all the default settings and without adding any columns, I got the following error:

The following is the full error text:

The SharePoint list form can't be customized with InfoPath because fields of an unsupported data type are marked as required, or because fields are corrupted. In SharePoint, try deleting the columns or editing the column properties to remove the required

Is this supposed to work for document libraries or is the ability to edit these forms in InfoPath 2010 limited to lists only? Like I said, I kept all the default settings and didn't add any additional columns to the document library so if this functionality is supposed to work, I would have assumed it would have worked at the very least in this scenario. But if it truly isn't supposed to work with document libraries in the first place, why does the command to edit the library's forms appear in the ribbon at all?