Warning for all RB4011 users do not install FW6.45.2 if you are using the SFP+ port, Installing the firmware makes the SFP+ adapter not seeing by the routerOS and no traffic throu SFP, downgrade to FW6.45.1 makes it work again.
I have no problem with FW6.45.2 on CHR and CCR1036
/Carsten