SSRS Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding

I have a reporting solution with several reports. Up to now, I have been able to add a dataset based on a SPROC with no problems. However, when I try to add the lastest dataset, and use a SPROC for its query type, when I click on Refresh Fields I get the following error: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. I have tested the database connection in Data Source properties>Edit>Test Connection, and it's working fine. I have increased the timeout to 100 in the following areas: - The connection string for the datasource, which is - Connect Timeout=100 - Tools>Options>Database Tools>Query and View Designers. Cancel long running query is set to 100. - Tools>Options>Database Tools>Table and Database Designers>Checked 'Override Connection String time-out value for table designer updates. Transaction time-out after is set to 100 The SPROC runs fine in the SQL database. It takes about 55 seconds. Any other ideas? Thanks. UPDATE: I now can't add any dataset with a SPROC. Even thought the SPROCs are all working fine in SQL!!!!!!