well first, changing the database collation does not change the collation of each individual varchar,char,nvarchar and nchar columns in the tables...so you'd still have the issues because those individual columns are still the collation they had before you started.

something i noticed was you were converting dates to varchars...i'd avoid that by doing this:

declare @report_id int

select @report_id = 1

declare @actiondate smalldatetime

select @actiondate = '2008-01-18'

select * from inow6.dbo.in_wf_item_arch

where queue_id in

(SELECT [object_id]

from report_objects

where report_id = @report_id

and [type] = 'Queue')

DATEADD(dd, DATEDIFF(dd,0,creation_time), 0) = DATEADD(dd, DATEDIFF(dd,0,@actiondate), 0)