default views with '$' in the URL accidentally get (non-functional) admin menu items

as mentioned at http://drupal.org/node/137911#comment-232337 i've got a patch that adds an enabled, default view to signup.module at user/$arg/signups. currently, this causes some funky UI problems for people with administer views: the "clone", "edit", and "export" admin tabs are added to the view, but none of them work at all. furthermore, these links are not visible at admin/build/views, only at user/$arg/signups. there's no reason these links couldn't work, but they don't ("edit" dumps you back at admin/build/views, "clone" gives you a 'Page not found', and "export" gives you a page with a text area that includes View '<em>signup_current_signups</em>' not found.).

copious use of dvm() and lots of truncate cache_views; truncate cache_menu; truncate cache; in my mysql window, has revealed the following tale of woe:

1. views_menu_admin_items() is adding these tabs for user/$arg/signups
2. it's the call to views_menu_admin_items() at the very bottom of views_menu_inline_items(), in the case for "// Do substitution on args"
3. the reason we hit that code at all with the default view from signups is that "/user/$arg/signups" is being returned from views_get_all_urls()
4. views_get_all_urls(), when looping over all the default views, if the view defines a page, it's enabled by default, and the url contains a '$' (e.g. because of '$arg'), then it gets saved in the $views array, which then stuffed into the cache with views_urls. (or, it just grabs the url out of the cached array).

so if you add all that together, you end up with admin tabs that don't work on default views that have a '$' in them. ;) i don't understand the views menu handling and all the parts of this puzzle well enough to know which part is doing the wrong thing, but the over-all behavior results in a buggy UI.

i'd be happy to roll a patch if i knew what to fix, but at this point, all i can offer is a (hopefully) clear debugging trail for merlin to make sense of. ;)

/me stands by to roll a patch if pointed in the right direction...