Query to add edited entries to the top of a paginated list

Hello, I have a will paginated list of properties and I'm trying to find
a way to display the most recently updated entries at the top of the
list based on their most current modify date. The approach I'm taking
is to use mysql UNION in paginate_by_sql and here's my code:

[code]

#property_ids is an array of property id's that have been edited
edited_list_where = " WHERE properties.property_id IN
(#{property_ids.join(', ')[0..-1]} )"

if(params[:page].to_i > 1)
  property_limit = " LIMIT #{property_ids.length} OFFSET
#{(params[:page].to_i*10)}" if (property_ids.length > 0)
end

Property.paginate_by_sql("(SELECT properties.*, layouts.* FROM
properties
                             LEFT OUTER JOIN layouts ON
layouts.property_id = properties.property_id
                               #{edited_list_where}
                                   ORDER BY properties.modify_date ASC
#{property_limit})
                          UNION
                             (SELECT properties.*, layouts.title FROM
properties
               LEFT OUTER JOIN layouts ON layouts.property_id =
properties.property_id
                  WHERE properties.property_type='apartment' ORDER BY
properties.property_status ASC)", :page => params[:page], :per_page =>
10)
[/code]

This approach works perfectly when you're on the first page and the
edited properties show up first ordered by the last edited, but when
you're on any other page, the edited list doesn't appear on top.

It seems like I'm asking quite a lot and I'm not sure this is even fully
possible w/out adding some complicated hacks.

Any ideas?

Thanks!
Clem C