Upgrade to 2.2 from 2.1 on X5A/X6D tablet

Dear all,
I would like to upgrade the firmware of my tablet
from Android 2.1 to Android 2.2 (Cyanogen possibly.. and when will 2.3 be available?).

I followed the guide I've found here, but apparently I make something
wrong because it doesn't work for me.

First of all, I've rooted my tablet using the app z4root.
I think it worked because if I open a terminal and
give the su command, it apparently changes to root.
As well if I install app requiring root access, they seem to work
fine when I confirm the permission.

If you think my tablet is correctly rooted, can you help me to figure
out why I can't upgrade the firmware?

I followed the instructions, but when I restart in recovery mode (using Clockwork),
it simply doesn't do anything. The tablet starts as usual.

Any suggestions?
Thanks a lot in advance for your help,
Cheers, -Luca