Hello Alfons,
Checking quickly in the Juniper page showed me that 7.2R6 is not listed.
https://www.juniper.net/support/downloads/?p=sa4500#sw
Actually, 8.0R1.0 from December 2013 is the oldest SP they list.
I would not be able to test as we do not have Juniper Security Hardware in-house.
Would you mind updating the Firmware of your Juniper SA/SSL 4500 to 8.0R6.0?
It is not for me to say this but for Juniper please consult your Juniper expert. I suspect that if your actual SP on Juniper is too old, it might be that Juniper already did something about this issue.
If the updated Juniper 8.0R6.0 still shows the same issue, please let us know.
Kind Regards,
Javier Puig
AGS Product Support