Querying ODBC SQL Server

Hi I've got a service setup to query a sql server via ODBC.

I've got all the parameters etc setup and everything is ok

My Query is

SELECT TOP 1
CI.ClientID, 
Gender, 
DateOfBirth, 
MaritalStatus AS MartialStatusCode,
(SELECT CodeDescription FROM GenMaritalStatus WHERE Code =  MaritalStatus) AS Martial,
Ethnicity AS EnthnicityCode,
(SELECT CodeDescription FROM GenEthnicity WHERE Code = Ethnicity) AS Ethnicity,
Nationality AS NationalityCode,
(SELECT CodeDescription FROM GenNationality WHERE Code = Nationality) AS Nationality,
DateOfDeath,
CN.Surname AS Surname,
 ISNULL (CN.GivenName1, '')
 + ISNULL( CN.GivenName2, '')
 + ISNULL(CN.GivenName3, '')
 + ISNULL( CN.GivenName4, '')
 + ISNULL(CN.GivenName5, '') AS Forename,
 ISNULL(CN.Prefix, '' ) AS Title,
 LastUpdated
  FROM [ClientIndex] CI
  INNER JOIN ClientName CN ON CI.ClientID = CN.ClientID WHERE LastUpdated > ?
ORDER BY LastUpdated

If I have my parameter as  

Do ..Adapter.SetPersistentValue(..%ConfigName,"LastModified","20080915")

This works. 

But if I add in the time part like this.

Do ..Adapter.SetPersistentValue(..%ConfigName,"LastModified","20080915 10:00:00")

I get 
ERROR #6022: Gateway failed: Execute. + ERROR <Ens>ErrGeneral: SQLState: (22001) NativeError: [0] Message: [Microsoft][ODBC SQL Server Driver]String data, right truncation

I've tried lots of different date/time formats but nothing seems to work. 

I've got a odbc sql browser and that works with this date format (yyyymmdd HH:ii:ss) 

So what gives here?

Thanks

Richard