Thank Amol and Satish,
These are SDP DB alerts (=DP mainly).
This is a bit weird but it appears like Alerts are not deleted despite the deletion programs of all kinds that exist are run. I wish I could delete them at a table level using sledge hammer.
Anyway this issue got magically fixed when I imported a new alert profile with new selection ID's (same masala inside) from source. For double safety I erased all goddamn alert profiles in the target. Erased without a trace.
Let SAP own the burden of explaining this magic to tortured souls. I don't care. It is working now. So I will claim to have solved the problem worth no more attention than 1 hour or 100 dollars whichever is les
Do not tell this secret solution to anyone :-).
Thanks
Amit.