Initially it worked like a charm. But then some where along those automatic upgrades and what not, the wifi became so unreliable that it could hardly be used--it can't be connected, it can't be authenticated, it kept disconnecting. Basically it can't be used. I had to resort to get a cross wire RJ-45 to join to my notebook wifi connection in order to fix it. To make a long story short. I have to go to realtek's super duper web site and download their Windows 64 bit inf file. I got the ndiswrapper program in my Ubuntu and the rest is just picking the downloaded inf driver file which couldn't be easier. But I really don't understand why the original Ubuntu or Linux module doesn't work over time. It got to do with maybe an upgraded kernel or something because it worked initially. Now I got my wi-fi back, and the signal seems to be more accurate instead of the like 126% that got shown previously.
update 10/6/2010:
Things just went downhill. But I stopped it from sliding down further.
Again for reasons I couldn't explain and I hate it when I couldn't explain what happened. The wifi stopped working again. I reverted it back to rtl8180 but the connection was extremely iffy. Very slow and sometimes the connection is no good. I tried to use WEP still no good. I wonder. Because like I said it worked out of the box up until a certain point.
In the end, I reverted back to ndiswrapper using the Windows 64 bit driver, namely netrtw.inf. I was able to get a realistic reading of the signal instead of something like 126% but poor connection, I got like 68% but pretty good speed considering it's a 11Mb b connection
here is my sudo iwconfig wlan0
IEEE 802.11b ESSID:"redacted"
Mode:Managed Frequency:2.437 GHz Access Point: 00:21:29:8A:F3:75
Bit Rate=11 Mb/s Tx-Power:20 dBm Sensitivity=0/3
RTS thr:off Fragment thr:off
Encryption key:F400-2D6C-EFAE-76F5-16D2-1751-76A6-A290-C249-8E81-DE00-ECF8-43B1-78F6-C312-5B90 Security mode:restricted
Power Management:off
Link Quality:67/100 Signal level:-53 dBm Noise level:-96 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:2019800144 Missed beacon:0
iwlist scan
lo Interface doesn't support scanning.
eth0 Interface doesn't support scanning.
wlan0 Scan completed :
Cell 01 - Address: 00:21:29:8A:F3:75
ESSID:"redacted"
Protocol:IEEE 802.11b
Mode:Managed
Frequency:2.437 GHz (Channel 6)
Quality:78/100 Signal level:-46 dBm Noise level:-96 dBm
Encryption key:on
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s
24 Mb/s; 36 Mb/s; 54 Mb/s
Extra:bcn_int=100
Extra:atim=0
IE: WPA Version 1
Group Cipher : TKIP
Pairwise Ciphers (1) : TKIP
Authentication Suites (1) : PSK
(note: screen capture on opening window doesn't work ... sigh, either entire desktop or selected area. what's wrong with these people?)
If I were using the rtl8180 driver sudo iwconfig wlan0 shows I have Encryption key:off which doesn't seem right. My guess is WPA doesn't work or work well with the native rtl8180 driver, actually the same can be said with WEP or no security. In other words, it doesn't work well at all, at least that's my experience for the past few days. The Windows netrtw.inf isn't flawless, there were a couple of times I couldn't get it installed with ndiswrapper but most of the time it takes it all right. So it's very very weird. Anyway, I rebooted the system a couple of times and it still works.
IF after a few days, it messes up again, then perhaps I would get a new PCI card for wifi G that supports WPA or other more advanced encryption technologies--does it make sense? I guess it doesn't.
UPDATE 12/29/2010
Just to give an update here. The wifi is still very much iffy meaning sometimes it just doesn't connect and sometimes it just drops the connection for no good reason that I know of. If you need a solid connection then it is not really working. One of these days I may just need to spend a few dollars to upgrade the wifi card. The router seems to be fine as all of my, okay not all as my good old Thinkpad R51 does drop connection like once a week or so, but definitely not as temperamental as the Ubuntu. Other devices, handhelds and notebooks work pretty flawlessly. I am on Ubuntu 10.10 64 bit now.