Thank you.v.m for your help.
I still get the bursting but it lasts now 1/5 second which is quite acceptable !
Setting AQAAdSU= and AQAA6yU= in my editor becomes 01000075 25 and 010000eb 25 (hex) which show an space not contemplated in what Hervé said. Does this space make any difference ? What are the right values?