RHEL 6.3 Workstation - Cannot Display Application back to Workstation

I have a customer that recently installed RHEL 6.3 X86_64 Workstation on an HP xw 9400.  They display several applications back from their application server to this workstation, but they cannot get the applications to display back with out using "ssh -X"  Are there any settings that can be changed to make this work properly?