Keep in mind transposer will only support poser 4, as far as I know. Since there are problems in poser and D|S between ver 4 and 5, no surprise there.I would think you would need to point it to ver 4 runtime. Trans2 included in c5 goes upto p5.For some models this might get tricky.Try pointing the runtime first, then if you think installing p4 only. I don't use poser currently so wish I could help more.The file associations can be changed manually(win anyway) at any point, but that may interfere w/ your poser usage and may not help w/ carrara.

No need to think outside the box....
    Just make it invisible.