Android tablet not connecting to Wi-Fi while previously did
I have resolved this issue myself. Here is what I did to resolve it:


Accessed wireless router's settings. Please remember I do not have access to ADSL router which is connected to the internet.
The linksys wireless router setting has "Wireless" menu. Under this menu, click on "Wireless MAC Filter". 
Click on "Enabled" radio button.
Click on "Prevent listed computers from accessing the wireless network" radio button. I saw a list of MAC addressed in this list. One of the MAC addresses was that of the tablet which was not connecting. I removed this from this list and VOILA!!!! my tab was happy :)


(I still don't know how it got into this list!!)