To describe in brief, my internet wifi faces problem where the internet pages don't load every few minutes and completely stop working. However I see that sometimes the services like skype or even gmail are unaffected. During this time the wifi symbol is continuously says that wifi is connected!
The internet returns after sometime and then the story repeats. Important to note that wifi works perfectly fine with the Windows 7 (dual boot). I have also checked this at my friend's home where wifi has problem with Ubuntu but not with Windows.
I have come across this post discussing the similar problem. Need to try that. However any better/permanent solution is welcome.
Edit: I have tried with WICD as mentioned in other links. It doesn't appear to be a great improvement for now. I have found one more askubuntu link which I am yet to explore.