Look at whether or not you have triggered a locking issue on the database.   I have caused SSIS to hang up / deadlock in a single data flow in my production packages.   The tasks in the data flow would be all yellow in BIDS, but no further activity in the package as the activity is blocked on the database.   You can see the locking issue with sp_who2 and sp_lock on the data base very easily.   I had a data flow with an OLE DB source, Lookup transform to determine if a record exists, an OLE DB destination for inserts, and OLE DB command for updates.   The package execution had to be cancelled and fast load option removed in the OLE DB destination. 

- Vince Napoli