OK i was having the same problem it was not able to see my video from my old HDD. i tried not rebooted and nothing. i then updated to PMB 5.5 same problem. when i connected my Sony camera PMB then said new features added for this camera and when i updated my data base it then found my video files.
Man, I'm glad I found this thread. I had re-installed the original PMB 5.0 (yes, I kept the install disk from the HDR-CS550V !) , and then all my vids would not show up. Rebooted , uninstalled, re-installed, was ripping what was left of my hair out in big chunks.
As soon as I plugged in the cam, a little window popped up:
And now all is well.
I saw some people writing about how PMB is not needed; true. BUT - it will seamlessly stitch together files larger than 4 GB into a single file, and give it a great name that contains the date/time of when the footage was shot, such as 20120829203331.m2ts . If you copy the raw files from your Sony cam and they are bigger than 4 GB for a single shot, even with a good editor such as Vegas Pro or Adobe Premier, when they are concatenated there will be a small drop in the audio.
If you still want to manually import the vids, and you need to join multiple > 4GB segments without any gaps, you can use good old COPY like this:
copy sourcefile1 + sourcefile2 + ... sourcefileN destinationFile /B