I've had this umbrella for two years now.  Had the same issue with small wind gusts as the others have.  Turns out I wan't opening it all the way.  On the underside of the umbrella make sure the center piece is snugged up tight to the shaft that comes down from the center of the umbrella.  Give it a good snug twist of the rotating handle so it's snug.  So much better now,  it's seen some big winds and have had zero issues when in the horizontal position.  In regards to the base, I filled mine with sand until full and then filled it with water.  Took about 1.5 bags of playground sand. I have to readd water every spring.  Have no stability issues now and I can still push it around the patio if needed.