Under the Admin advanced login, PSTN Line tab, PSTN-To-VoIP Gateway section, make sure PSTN CID For VoIP CID is set to "yes". Also, with the 3.x firmware update, I had trouble with using a hotline forward to * -- CID was seen but not forwarded with the SIP INVITE -- so I went back to the prefix/selective call forward method described in the Sipura forum. Works like a champ.
Have you confirmed that the
SPA-3000 is actually getting CID from the PSTN?