Test you Cisco ASA or PIX ACL (access control list) to see if the ACL is permit traffic or blocking it.
Example command – packet-tracer input inside tcp 10.1.1.1 1024 10.4.1.1 23
What is the expected output command in an allowed flow situation?
primary# packet-tracer input inside tcp 10.1.1.1 1024 10.4.1.1 23
There will be 9 or 10 more phases before this. If the Action is deny then look at those phases to determine what is blocking or denying your IP traffic.