select_tag problem or a seve (me) problem?

I'm trying to use the select_tag with :multiple => true and when it posts to the server it's generating "---" followed by a "-" and each selected option. I have no idea what I'm doing wrong... Any help is appreciated.

Code in the view:

<%= select_tag 'restaurant[holidays]', options_for_select (["Independence Day", "Thanksgiving", "Christmas Eve", "Christmas Day", "New Years Eve", "New Years Day"]), :multiple => true %>

After making the selections I end up with this in the log:

"holidays" = '--- - Independence Day - Thanksgiving - Christmas Eve - Christmas Day - New Years Day

HTML rendered from said action:

--- - Independence Day - Thanksgiving - Christmas Eve - Christmas Day - New Years Day

Cheers, Seve

The --- part is the list of selected holidays in YAML - what kind of field are you saving them to?

--Matt Jones