SQL Server 2005 SELECT TOP 1 from VIEW returns LAST row

I have a view that may contain more than one row, looking like this:

[rate] | [vendorID]
 8374       1234
 6523       4321
 5234       9374

In a SPROC, I need to set a param equal to the value of the first column from the first row of the view. something like this:

DECLARE @rate int;
SET @rate = (select top 1 rate from vendor_view where vendorID = 123)
SELECT @rate

But this ALWAYS returns the LAST row of the view.

In fact, if I simply run the subselect by itself, I only get the last row.
With 3 rows in the view, TOP 2 returns the FIRST and THIRD rows in order. With 4 rows, it's returning the top 3 in order. Yet still top 1 is returning the last. DERP?!?

This works..

DECLARE @rate int;

CREATE TABLE #temp (vRate int)
INSERT INTO  #temp (vRate) (select rate from vendor_view where vendorID = 123)

SET @rate = (select top 1 vRate from #temp)
SELECT @rate

DROP TABLE #temp

.. but can someone tell me why the first behaves so fudgely and how to do what I want? As explained in the comments, there is no meaningful column by which I can do an order by. Can I force the order in which rows are inserted to be the order in which they are returned?

[EDIT] I've also noticed that: select top 1 rate from ([view definition select]) also returns the correct values time and again.[/EDIT]

Solution

While it doesn't necessarily make sense that the results of the query should be consistent, in this particular instance they are so we decided to leave it 'as is'. Ultimately it would be best to add a column, but this was not an option. The application this belongs to is slated to be discontinued sometime soon and the database server will not be upgraded from SQL 2005. I don't necessarily like this outcome, but it is what it is: until it breaks it shall not be fixed. :-x