Final Cut Pro X :: 10.1.3 Does Not See Camera Archives?

I have tried to use the "camera archive functionality" for the first time and got a problem, I can't solve myself: 

I plugged a SD-Card with content of my Panasonic SD 909 into my Mac and opened FCPX. Then I went to the "Import Media"-Window. The card is shown twice. I think, this is, because it contains different media. Some clips shot in Panasonics "iFrame"-Mode (which leads to h.264), some shots in the well-known AVCHD-mode. First is shown in the one camera-card, second in the other. Importing media from this card(s) into an FCPX event works without problems. 

No I activated one of the two cards in the upper right panel and clicked on "create archive" (or similar, I use the german translation). A window pops up where I can choose the destination for the archive (I have chosen my desktop first). I did not activate the option "create favorite" for now and started processing. 

It took a long while (about 18 GB of data), but then the archive was created and in the finder, I can see it on my desktop. Annotation: Selecting the first or second camera-card for archiving leads to the same result. In both cases a archive was generated which stores both contens (approved by examining the package size and content in the finder). 

But now, the problem(s):When I go to the import window in FCPX again, the archive is not visible. It does not appear in the left panel of the import media-Window. Not as a camera, not as a device, not as an archive. Restarting FCPX and even my Mac does not solve this.I can navigate to the archive via choosing my harddisk/desktop in the left panel and can see it in the "choose media section" in the bottom of the window. It behaves like a folder there. When I open this folder, I only see the h.264-media, but no AVCHD-Clips. This happens, regardless which card I have choosen when generating the archive (tried it with both, and - as said - both ways result in the same archive). 

What am I doing wrong? I know, in older versions of FCPX, archives had to be stored in a special folder inside the movie-folder of my user, but this has changed with 10.1.2 and the folder is not there any longer. Is there an other place for the archives? I thought, starting with 10.1.2 it's no matter, where to store them... 

Or is this a bug in FCPX (10.1.3)? 

If this is on interest, my OS is 10.9.4, the complete system nearly a "virgin" (fresh complete install). 

Info:
iMac (27-inch, Late 2012), OS X Mavericks (10.9.4)