I have a Crystal Reports 2008 user that has over 100 custom developed reports.
The reports all query Sql Server databases (SQL 2005).
This database server is getting rep
Choose Database | Set Datasource Location... Select the database node (yellow-ish cylinder) of the current connection, then select the database node of the desired connection (you may need to authenticate), then click Update.
You will need to do this for the 'Subreports' nodes as well.
FYI, you can also do individual tables by selecting each individually, then choosing Update.