iSCSI HBA Windows 2008

Our server connects to an ISCSI SAN (AX4) via a dual port Broadcom 5709 NICs with toe and iscsi support.  The ports show as storage adapters (two of them) in Win2K8 Standard 64bit OS.  I configure the HBA's through iSCSI initiator that's installed by default on Win2K8.  First I assigned the NICs (HBAs) static IP in its own VLAN (created for iscsi traffic).  

In iSCSI initiator properties window > either from discovery or target tabs > advanced settings window to configure the adapter > local adapter drop down > I see four options (defaut, 1st iscsi hba, 2nd iscsi hba, ms iscsi initiator).  When I select either iscsi hba > then under source IP I only get two options (default and hexa characters for iqn or wwn).   When i select this, I get some transport error.  However, when i select the MS iscsi initiator, then under source IP, I get the IPs I set on the HBAs/NICs... this works like a champ.  

Is this how iscsi HBA is configured?  Since I am selecting the IP I assigned to the HBA/NIC then traffic goes through this, so would the HBA off load the processing from the OS/server CPU, etc by default?  Why are the two HBAs show up on the drop down as described earlier if it can't be configured that way or am I just missing a step.

Please advise.

Thanks...