Using 'IN' operator in ColdFusion Query of Queries throwing error

Hi,
I have the following query which is throwing an error:

<cfquery dbtype="query" name="getAtt">
select *, upper(lname) as ulname, upper(fname) as ufname from getAttendees
where breakout_id = '#trim(url.ids)#'
and id_register_status IN (1,3)
and id_rate_type NOT IN (1,2)   (this is the line that's breaking it.. causing error)
order by date_signup
</cfquery>

The datatype for id_rate_type is VCHARAR2 - Oracle DB.

Here's the error message:

Query Of Queries runtime error.  
Comparison exception while executing IN.
Unsupported Type Comparison Exception: The IN operator does not support comparison between the following types:
Left hand side expression type = "STRING".
Right hand side expression type = "LONG".


Any help resolving this will be greatly greatly appreciated.
Thank you  ~ Wendi