Meridius,
finally, I got Lubuntu 10.10 working. Everything's fine, now.
To solve the problem with the wireless card I applied the suggestion found in
this thread.
According to the explanatiohns given, it looks like some firmware included as binary files in 10.x replaced the one already available in the wireless card. Therefore, removing the "firmware" that Lubuntu installs forces the card to use its own, which is perfectly operative. The only drawback is that the Portégé's built in card is not able to deal with WPA authentication, so WEP is the maximum level of security achieved (at least, this is what I had to do: downgrade my router from WPA to WEP authentication).
FINALLY I have my Portégé 4000 working as if it was 5 years younger! It's taken more than I week, but the results are worth the effort.
Yesterday I decided to watch a movie, since this seemed to be one of the more CPU demanding activities and the experience with Puppy was a little bit disappointing. Well, I have to say that the player included in Lubuntu (I can't remeber which one it is) performed very well even at full screen resolution. I only got skips when I moved the mouse, so the player controls where shown or hidden. If the mouse remained stopped, there were NO skips at all.
So I strongly recommend you to go for Lubuntu 10.10. However, if you ever test the solution related to Puppy 5.2, let me know what happens. I'm not willing to reinstall Puppy 5.2 now that Lubuntu 10.10 is working just to check if that trick works.
Bleriot.
