Don't have enough information to fully understand why that happened so let's proceed with reasonable inferences. We will assume that you've created the splice at a single location on the network as recommended in the Pre-requisites doc http://communities.mentor.com/docs/DOC-1618 under the section Splices. The important points in the section are the splice needs to have a single entry port and created using default Pro/E methods. Of course, other standard Pro/E-side things like setting num_of_pins=1 and type Splice are a matter of fact. (Clearly you had done these that is why it was exported with just the network.)
If the above is true that that is how you've modeled the splices onto the network, and because it is true that the splice did get exported out when you had just then network, that implies that the plugin version you have has no defect on this count.
If you notice that after you routed the wires (or/and created insulation bundles) the splice(s) did not get exported, I'd ask that you keep the wires and insulations in the model, but when you export the xml, don't check the box to export the wires. Typically you don't need the wires to be exported. If you find the splice(s) continue to be present, the plugin is fine.
Now export again with the Export wires box checked. I suppose this is what you had done, and found the splice(s) are not present. If so, this clearly implies a defect (but one that I have not seen so far). If so, please zip the .asm up and send to me at firstname.lastname@example.org. I'll need to confirm your findings, and if its a defect will request you to file an SR.
Please let us know the Capital release and its SP that you are on.
Thanks for your response, I have found the solution.
the issues in Pro/E component parameter "type".