DHCP Issues on Nortel ERS-5520

[180990]

After upgrading switch to software release 6.1.3.025 secured. Any device that is attached to any port will not receive an IP address assigned by DHCP server.
I've captured traffic going from the device and requesting IP. The request comes to DHCP server. DHCP server receives request and responds back with IP assigned to device, but device will not receive the response back with IP assigned to it. Checked relay agent and dhcp relay agent fwd path, everything is there.
DHCP server is Windows 2003 R2 Sp2
Anyone has any ideas what might cause this problem?

Thanks in advance

 

[VinceWhirlwind]

Are your switchports dot1q trunks or just in an untagged VLAN?

Do you have raPID SPANNING-TREE ON?

 

[FinGo]

Try to disable the Rate-Limit on the Uplinks