Android tablet not connecting to Wi-Fi while previously did I have three devices:


Tablet running Android 2.2; (WPAD)
Tablet running Android ICS; (Samsung Tab 2)
A laptop. (Dell Studio 1558)
Wirelss Router: WRT120N (Linksys)


Wireless Router access is protected with WPA/WPA2 PSK. I can confirm that password given is correct. 

My laptop (3) and Android ICS tablet (2), both connect fine to the wireless router.

But my other tablet (1) doesn't connect, it keeps "Scanning" and then disconnects. This tablet used to connect to router earlier, but now it does not. I have also observed that after a few seconds the wirless network is shown as "Not in Range, secured with WPA/WPA2 PSK" and then comes back with message "Remembered, secured with WPA/WPA2 PSK". So I am also not sure whether it is the problem with the tab!

Android ICS (2) is my new Samsung tab 2 tablet, so I have no idea whether this is caused due to new connection or not? To ascertain this, I have tried connecting only the first tablet (1), but still not working :(

The wireless router is connected to ADSL router provided by service provider. The ADSL router settings are password protected, i.e I cannot view ADSL router settings through web browswer.

Any thoughts on what could be causing the tablet to be losing the connection?
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!!)