I flashed my 770 with os2006 a few days ago. Now I am trying to install applications. Whatever I do, Application Manager will respond with "operation failed".

The log file contains the following lines:
apt-worker exited
write: Bad file descriptor

I tried to reset the 770, it did not help.

Which applications are you trying to install?
Note that .deb files from the 2005 OS will not work in the 2006 OS.

You need to be sure that you are attempting installation of IT2006 apps--the "built-in" selections should be ok. Also, I imagine your WiFi connection needs to be solid.

Nope. I tried OS2006 applications from a downloaded file, I try to refresh the list, I try to list the already installed applications... Everything fails.

I think that the file which holds the list of downloaded applications is corrupted. Where is it?

Since you haven't installed anything yet on it, obviously, just re-flash the device with the 2006 OS image? You might have to download a Linux Live CD and the flasher-2.0 program but that's hardly difficult (get Knoppix, start it, fire up the web browser and download what you need and then flash your 770).

Seems to me it is quite possible something didn't go right when you flashed yours the first time.

I was hoping there would be a simpler solution.