web service Script task vs Script Component

Hello Every one

Version:Sql server 2008 BIDS 2008

I can able to call a web service  and methodsin script task in a control

flow task 

I am using similar code in a script component as a transformation because i need to perform some task using return data from web service which takes 4 inputs and returns 1 output

Every thing works great in contro flow but same script fails in script component with error

Fial STATUS HTTP 401:UNAUTHORIZE

If i was not authorize user it should have failed in control flow script task

script is similar to this

var service=sc_123.csproj.webservicename.servicename()

service.methodname(parameters)

I dont understand the reason it fails in data flow task

Appreciate for suggestions

Thanks