I have a droid charge and when i connect to wifi the only internet page i can visit is facebook, if i try to go anywhere else (msn, pnc bank, any page at all) i get a message saying "web page not available"....to every page i try to visit....so wifi is completely useless to me on my phone. about the only thing i can use it for is when i want to upload a picture to facebook because its faster than my phones internet, which will upload about 20-40% and the about 15minutes later my internet tells me my picture couldn't be uploaded. my issues with this phone:
can't send videos to anyone via email or messaging
videos uploaded to facebook disappear from my gallery
wifi only works for uploading pictures to facebook or to visit the facebook page
internet doesn't work for uploading pictures
thats what i can think of right off the bat..for now.
No internet while on WiFi is no fun. Let's work on resolving all issues. Run in safe mode http://goo.gl/dxV1i and test. If issues do not occur while in safe mode, you have a 3rd party application conflict. No easy way to identify such conflicting app. You will have to remove all 3rd party apps and install one at a time and test between installs to identify bad app and remove for good.
A corrupted system file may also cause the issues outlined in your post. Do a factory reset http://goo.gl/tbjkt and test before installing any 3rd party applications. Keep us posted.
If youre not able to access anything other than facebook (yuck) on wifi first of all, my sympathies. Secondly, unless tis on every wifi connection in the world on that phone its the wifi's connection, not the phones fault.