Wow Liz, that worked, thank you so much. BTW I called Apple tech support and they told it is impossible to import AVCHD files without embedding them into FCP.
Anyway, Here’s what worked for me:
1-Copy the PRIVATE folder and all its contents from the camera SD card.
2- Open the PRIVATE folder, right click the AVCHD Icon and select ”show package contents”, this will reveal an icon called BDMV.
3- Right click the BDMV icon, and select ”show package contents”. This will reveal a folder called STREAM.
4-Open the STREAM folder and select the clips you want. They will be named 00000.MTS, 00001.MTS, and so on.
5- Drag the clips onto FCPX. There will be no progress bar, just the deadly colored spinning wheel, but fear not. If there are many large clips, go meditate. Eventually the clips will appear in FCPX. And no, the file size of FCPX will not suddenly jump to 50GB.