Poseidon 2?? It is up to V3.x these days and you can d/l the demo version off Chris Hodges' website:
You can even register Poseidon again for Thylacine if you think it's worth the money:
Obviously Sirion is bundled with the Thylacine card and the package comes at a very good price, but support for USB devices looks to be limited (if you look at the Thylacine website) and it hasn't been updated for quite some time (and won't be anytime soon according to the author). That's why you probably didn't have much luck with the devices you tried initially.
Still, if you're managing to find devices that work with Sirion that aren't listed on the Thylacine website, then tell us (and Robert Tsien) about them. I'd be interested to know as I have a Thylacine card too, but haven't installed it yet.