Comparing A Real Datetime To A 'constructed' Datetime

I have the following SQL:

select convert(datetime,'04-20-' + right(term,4)) as dt,
'Deposit' as type, a.* from
dbo.status_view a

where right(term,4) always returns a string which constitutes a 4 digit year eg '1999','2004',etc.

The SQL above returns

2004-04-20 00:00:00.000 Deposit ...

Which makes me think that it is able to successfully construct the datetime object inline. But then when I try and do:

select * from
(
select convert(datetime,'04-20-' + right(term,4)) as dt,
'Deposit' as type, a.* from
dbo.status_view a
) where dt >= a.submit_date

I get the following error:

Syntax error converting datetime from character string.

Given that it executes the innermost SQL just fine and seems to convert the string to a datetime object, I don't see why subsequently trying to USE that datetime object for something (in this case comparison with submit_date which is a datetime in the table a) should screw it up. Help!!! Thanks...