Thanx Stefano.
I spent all last night trying out different solutions and FINALLY decided to change the channel on the router and EUREKA, the signal was much better and did not disappear. In case anyone has the same problem - the Router is a TP-Link ADSL2+ model and was originally set to channel 1. On my other devices - Galaxy S2,S3, Galaxy Tab - there was no problem in connecting, only with the Note 2. Guess there was some interference on channel 1 that the Note 2 did not like. Thanx again. Ciao