Comment 32 for bug 139832

I can also confirm that this driver is buggy. I have D-Link DWL-G510 rev C2 (RT61) that I tried to use on a fresh Ubuntu Gutsy 7.10-i386 install (updated up to date by 2007-12-18).
The hardware is detected and scan the area just fine. It finds my wifi-network, but I can't connect to it (WPA/WPA2-protected). I read something about disabling SMP and PREEMPT, and rebuild the kernel to make the CVS-driver work correctly, but that workaround will generate a lot of work to keep the kernel up to date in the near future, I guess.

I ended up solving the problem by installing ndiswrapper and use the xp-drivers bundled with the hardware (version 5.00).
I did as follows:

$ echo 'blacklist rt61pci' | sudo tee -a /etc/modprobe.d/blacklist
$ sudo apt-get install ndiswrapper-utils-1.9 ndiswrapper-common ndisgtk

And then I started the graphical ndisgtk from "System > Administration > Windows Wireless drivers". The hardware was found automatically and I added the drivers directly from the bundled install-cd ( /cdrom/Drivers/Drivers/Win2kXP/NetRt61G.INF ).
At last I rebooted and after that it has worked 99% of the time together with network-manager (the wifi-card looses signal strength down to ~20% some short periods of time, but nothing that has affected the connectivity).

I will keep it this way until there is a working, stable, native driver available in the main repository.

I hope this can help some of you that want to get your DWL-G510-card working.