I'm pretty sure the card only has one folder - the BPAV folder. That's all I've ever seen. What I do when capturing from the card to the hard drive is create a series of folders: 001, 002, 003 ... each representing a chronolgocial capture from a card; and put the related BPAV folder in each numbered folder. I'm often capturing non-stop on jobs – those two hours at the end of the day when everyone's gone to the bar and I'm still in my hotel room capturing and backing up.
When logging and capturing I go to that numbered folder click on it (but DON'T highlight the BPAV folder): I highlight the folder that the BPAV folder is in, and FCP automatically SEES the BPAV folder.
I'm often changing the XDCam files to ProRes now - as I use a Samurai recorder on the camera, and record a lot in ProRes HQ.
There is a wonderful app called NameChanger. I love it. All XDCam files are numbered in-camera. I've found it easier when editing long films to change the numbers to names - for example naming a set of shots as a particular scene. NameChanger lets me batch change a hundred shots in a nano-second, smooth as glass. I realise this is an issue if I ever need to go back to the orginal BPAV folder and files (locating them), but I've yet to have to do it, and once everything is in ProRes HQ, there is no real point in going back - unless I have the misfortune to have to make changes on the film using an entirely different edit setup. Unlikely.
I confess that once I got over that orginal glitch (the missing plug-in) the FCP7 on this computer has been capturing XDCam seamlessly for the last two years.
All the best,
Ben