Log size is depend on the transaction. If you are running huge transaction, it may cause big log file. Are you running any INDEX REBUILD or INDEXDEFRAG commands? If so then it may be the effect of huge log file.
Run the DBCC OPENTRAN and see if there are any open transactions? Run the profiler and see who is doing what which is causing such issue.
In each OLE DB Destination - there are 2 options that you can set that will control how large the batch size and commit size are. Setting those options will 'batch' your inserts and commit the data, allowing the transaction log to be reused.