I have two Acer notebooks with Inprocomm IPN 2220 Wireless card and the card is not supported out of the box by all known versions of Ubuntu. Given the limited experience with Linux in general, this is somewhat frustrating when the OS lacks complete hardware support.
By reading this notes on installing Ubuntu Linxu on Acer TravelMate 2304WLMi by merriam, it helped. I tried the same steps with Ubuntu 8.04 but did not work; because the steps are slightly outdated. The modified steps are:
0) Load Ubuntu 8.04 CD or install Ubuntu; log in to the system
1) Click Applications -> Add/Remove...
2) In the Search field, type "ndiswrapper" then select Ndiswrapper driver installation tool and click Apply Changes
3) Complete the installation
4) Click Applications -> Accessories -> Terminal
5a) wget ftp://ftp.support.acer-euro.com/notebook/travelmate_4000/driver/a802.zip
5b) unzip a802.zip
5c) sudo cp -r A802/ /opt/
5d) sudo ndiswrapper -i /opt/A802/Winxp/neti2220.inf
5f) sudo ndiswrapper -m
5g) sudo modprobe ndiswrapper
5h) sudo ifdown eth0
5i) sudo ifup wlan0
6) Click on the network icon, click Create New Wireless Network...
7) Type in the Network Name, select Wireless Security, type Key, then click Connect
8) Complete the process.
Note: if the wireless did not connect, try single click on the network icon and try the connection steps 6~8 again.