Wifi really slow in Ubuntu

[Heavens]

I just switch to Ubuntu and miracle, I finally managed to have a connection without a penny (before I was on Debian and impossible to set my wifi).

So far so good, but my wifi is very slow and its scope is really poor, I can not go in my room which is on the floor while it works perfectly under Vista and other wireless equipment.

To avoid unnecessary long code, I copied in a pastebin

http://pastebin.com/f767fc90c

I'd like to know where the problem and be able to adjust more quickly, I'm Ethernet at this time.

Thank you.

[robodude]

Me precisely the opposite, my laptop detects the best wifi in ubuntu (9.04) that under vista, it must surely depend on the model.

[Dr. V]

Try this:

 iwconfig wlan0 rate 54M

See also if you can increase your power output

[Heavens]

Thank you for your response, I tried the command and no change.