Thanks for your answers but none of your suggestions worked, I have ended up using a basic turnaround :
UVC.JavaEdit("JTextField").Set"admin"
UVC.JavaEdit("PSW").Click 1,1
UVC.JavaEdit("PSW").SetSecure"52581237d889935df36ae78587773a641f40"
UVC.JavaButton("Connect").Click
wait (5)
While JavaDialog("Login Error").Exist
JavaDialog("Login Error").JavaButton("Ok").click
UVC.JavaEdit("PSW").RefreshObject
UVC.JavaEdit("PSW").SetSecure"52581237d889935df36ae78587773a641f40"
UVC.JavaButton("Connect").Click
Wend
I really don't get it how could the same function work sometimes and sometimes not!!