Anyone any simple and cheap ideas on how to stop this:

http://www.howhill.com/weather/view....2005&m=04&d=28

Happening again (5 years ago it was only the roof that went flying)...

The "base" is just 4 4"sq posts laid on the ground, for the joists to
rest on, so no gert concrete lump to bolt it to. Are the corkscrew
spiral or disc type "ground anchors" any good?

I had problems with my shed in our side passage "wondering up and down" in
strong winds, though not blown over, despite it being full of cr*p. Anyway I
placed two long 4x4 fence posts in the ground about 2-3ft deep, set in
morter and bolted the shed to the posts. Shed hasn't moved since. Mind you
everything else still blows up and down the side passage. One day couldn't
get in via the gate as all the garden furniture and kids toys had been blown
down the passage and piled up behind the gate.