Aptitude problem when upgrade to lenny

["B. Liu" <bl246@hermes.cam.ac.uk>]

Dear All,

I am in the middle of upgraing from etch to lenny.

I run apt-get update. This complained about an unknown key.
Then run: apt-get install debian-keyring debian-archive-keyring
and run: apt-key update
then run: aptitude update
then run: aptitude install apt dpkg aptitude

However when unpacking the apitutde package, it simplely hangs. The message is:
Preparing to replace aptitude 0.4.4-4 (using .../aptitude_0.4.11.11-1~lenny1_amd64.deb) ...
Unpacking replacement aptitude ...

I download the aptitude_0.4.11.11-1~lenny1_amd64.deb package, using dpkg to install, it hangs as well. My machines is dell poweredge 1950 64-bit Quad core.

I am not on the mailing list, please reply to my email as well.

Thanks

Bin