The ability for multiple views to have the same path for their page displays. Specially for taxonomy/terms/tid.
I write the solution founded in http://drupal.org/node/278651#comment-2576586
Views can't resolve it, but it can be done when using the attachments display.
Create an attachments display with these settings:
Inherit arguments: Yes
Inherit exposed filters: No
Inherit pager: --> not important
Render pager: --> not important
Attach to: Page
Then override the arguments (and also filters if required) for this attachments display.
Also make sure that when arguments do not validate you chose: "display empty text"