I just started playing with Quick Data (reporting Server 7.6.3 Windows) but I am baffled by the Data Source Selection list. What is the criteria by witch is it chosen? We have 2 environments dev & prod; in one the APP PATH is "ibisamp dir1 dir2 baseapp" and the masters shown are from dir1; in the other APP PATH is "dom1 dom2 baseapp" and in EXCEL we get the message 'server returned no data source!' Can someone explain to me how does it work? Thanks

"Server returned no data source" is what you would see if there were NO masters in your list of applications. I suggest you validate there are masters available for that user with:
TABLE FILE SYSTABLE
BY NAME
END
... Do not forget to look for USERID profiles that may be clearing your edasprof APP PATH.