I have the same device and have the same problem, so I'm interested to hear from someone who can help us out. I'm wondering what version of WLAN driver you have. I have 3.2.2.84 and Firmware 0.100.5.39
Have you tried changing all the "internet" and "work" settings to either all "internet" or "work"? If you've tried that take the battery off and push the reset button about 5 times or so. I've never had to do that but I have seen posts where that method has worked to restore network connectivity.
Removing and replacing the battery at least helped the settings stay on what I selected. I will try to reconnect once I get back home to the base station.
This solution was also given to me by HP support when I couldn't get my WEP key entered properly, so re-setting the unit looks like a frequent activity. :?
I managed to reconnect to the web - for awhile. But now it takes forever to load a browser and I think I'm back where I started. Plus, I still cannot send an e-mail Wi-Fi. So, I'm getting frustrated. Hope you are having better luck.