Add New Field Now Cant connect to DB

Hi

This is a new thread and leads on from a related question I have posted earlier in another thread. I am running CR9 into SQL Server DB. I wanted to add a new field to the report so here is what I done:

Went into appropriate view that shows procedure of original report in SQL Server DB.

Right clicked on the view > design view

Ticked column I wanted to be included in report

Saved

Went to CR9 and reconnected to DB through ODBC

Selected new column from list in field explorer window and added it to report.

Now I have this problem every time I try and preview the report;

login failed. Details: 28000[Microsoft][ODBC SQL Server Driver][SQL Server] login failed for user 'sa'

But every other report in the report designer works bar this one that i've just changed.

How can this be a login problem through only changing a field and why can I get every other report running?

Does anyone have any idea as to where I should start looking to fix this?

Thanks

G