Backup of Truecrypt-encrypted system drive?

Hi,

how am I supposed to backup a Truecrypt-encrypted system drive? Is it possible? Out of running Windows?

So far, I did it that way:

- backing up in the usual way under Windows
- restoring without MBR and Track 0 by using BartPE
- writing new MBR using BartPE
- boot
- encrypt again using Truecrypt

This, of course, works well, but is somewhat time-consuming.

Cant it be done by "sector-by-sector" backup and restore as well?

I tried that too and all looks fine, even the original Truecrypt bootloader shows up after restore and boot - but after entering the password, Windows wont boot. Whats wrong?

thank you