I just had the same problem.  If you bought the plants/objects when you only had Vue 5 then they are locked into Vue5.  In order to get them to work for Vue 5 INF you will have to contact the support at Cornucopia and have them reset all your down loads so it will work in Vue5 INF.  Once they due this the downloads will not work in Vue5, so make sure you have a local copy of them in case you want to use them in Vue5.  For now whenever you purchase something from Cornucopia make sure Vue 5 INF is selected at the top of the check out page.  The techs inform me they are trying to correct this, but that's the work around for now.  Hope this helps:)

Stew