repliacte data source one more time if it is not successful check error and check connections in SM59.
RS_TRANSTRU_ACTIVATE_ALL ,also there is similar program for data source which u can try as well.
try full repair load and see if it works..see if there is any issue with delta mechanism and respective table.delete init and try one more time..
see if any set up table fill up is required in case of 2 LIS data sources..
Thanks and regards
Kiran