i am giving up on the Mallenox MC3309130-001 copper cables. I used on both sides Cisco SFP-10GB-sR and single mode fiber - works like charm. Even using juniper EX-SFP-10GE-LRM-OEM on both sides and single mode fiber would not work. I dont think that Mallenox copper is compatybile in this scenario.
Simply Cisco SFP-10GB-sR on Juniper 4300 and 4900M sides with single mode fiber works the best. Thank You again for help.