Sony AX2000 wrongly indicates Media Full condition
 

I own an HDR-AX2000E (PAL Version in Germany) and are using 32GB Sandisk SD cards as recording medium. When I came back from vacation where I has shot about one and a half cards full of film and loaded the data to my PC I noticed that the first card which became full when I was shooting videos, still had about 5 GB free space. This was not only indicated by the Windows Explorer but also by the Status Menu of the AX2000. Also the added time of recorded footage was only 145 mins. I then started to shoot some random footage just to fill up the second card and had a similar result: At 163 mins the camera indicated that the card was full but the Status Menu and the Windows Explorer both showed about 4 GB free space.
I talked to the SONY service people about that but they could not, even in their dreams believe that I had such a problem.
So what am I going to do? I believe there is some software bug in the camera which wrongly calculates the remaining recording time. May be this problem happens only when using 32GB cards? I would very much appreciate if someone could verify this phenomenon. Again, I am using the AX2000E PAL camera, which may be slightly different from the US version.
Anyway, any help on this is very welcome.