like collin said, step 4 is not needed.

is nat-control enabled? what is the security level of each interface? are there any nat rules in place?

have you allowed inter-interface communication as previously suggested?

same-security-traffic permit inter-interface

are there any acl's on any inside interfaces?

we really need to see your config to see what the problems might be.

Config uploaded as request. Thanks!

Here's a link on NAT-Control. Basically this turns off NAT between your internal subnets and "routes" the traffic.

http://www.cisco.com/en/US/products/ps6120/products_configuration_example09186a008046f31a.shtml#backinfo

http://www.cisco.com/en/US/products/ps6120/products_configuration_example09186a00807fc191.shtml

In case you need config example for the sub-interfaces-

http://www.cisco.com/en/US/docs/security/asa/asa80/configuration/guide/intrface.html