I have this problem sometimes also, but only with Poser runtimes 4-6 since I don't have 7.  I think it has to do with which primary Poser version you tell carrara about and then it asks you to find geomoetries and textures if they're in a different runtime than that version.
Keep in mind, I don't have my version in front of me now, so I could be way off base.  But once I tell Carrara where to find the geometery for one item, thats all it takes.

Oh yeah... and I use a PC, not a Mac, so there might be some differences there also.