working on built-in reports and RI in parallel
Accepted answer
If RI is pointing to the same data warehouse as the one used by the built in reports (which is the normal case), you should turn off the internal java etl. There are additional ETL that come with RI that should/need to run, ie, the RI ETL is a superset of the build in java etl. Both report sets will function fine as they are only doing read only operations against the data warehouse