I had the issue and did some testing based on some of these posts. I've used Titanium Backup since being rooted on my D1 so typically when I would root/unroot/root etc I'd just restore everything from backup. I started to use one of the WiFi fixers but when starting it saw the "this will delete all profiles message" I stopped and did not run the fixer. So I just deleted my profiles and rebuilt without the outside help. Now everything works fine with Wifi and I never had an issue with the 3G service. In fact when the WiFi would stop working I could just turn it off and the 3G would pick up on the web page that was hung up.
If I didn't read close enough and you'd already tried this, sorry for taking up the time and space.
I've been on my new phone since tuesday. I used wifi a lot at the house(several hours each day) with no problems. I'm back rooted also. I used the same rooted version of gb(was already on my sd card) Now I haven't put liberty back on but I was having wifi problems on the old phone in before liberty away.. Just wanted to make that clear incase someone thought the problem was cause I was rooted with a rom..
I had the same problem. My wifi would connect for about 20 seconds when turned on, and then would be connected, but I would have no internet activity. After starting and restarting the wifi, it would repeat the problem. I went into settings>wireless & networks> Wifi Settings> :Click menu button one phone: Advanced> and then checked the option enable auto IP. I had this unchecked before, and was going crazy trying to get my wifi to work. Seemed to fix the problem for me. Gl everyone.
If you're having trouble and need help you should start your own thread with details about what your issue is, what steps you've taken to try and fix it so far and what software version you're running. This thread is over a year old and your post doesn't really explain what you're trying to do.