I purchased Asus EeePad Transformer (used) from someone and tried to connect to my secured router. Failed. It read, disabled secured with wpa/wpa2. Tried many time but did not work. Asus tablet has genuine Android 3.1 on it. My secured router is secured using WPA2 with "passphase". Then I bought a NEW Tablet (not a well known brand) with Android 2.3 and tried to connect to the same secured router with same settings. Worked without any issue. Recently I bought a used Samsung Galaxy tab from someone. Tried to conenct to the secured router but failed. Galaxy tab has genuine Android 3.1 on it. Is the problem related to 3.1 or there is something else I should do (but its working on another tablet)? Another difference is that it worked on a brand new tablet but failed on two tablets that I bought from someone (but both of these tablets have original Android 3.1 on them). Should I apply factory reset?