[ubuntu-uk] Cannot resize windows (U9.04)

[David King]

I have been using Ubuntu 9.04 since it was released, but today I have 
found that I can no longer resize any windows. I put my mouse cursor 
over the bottom right corner, it changes to the resize symbol, I click 
and drag, but nothing happens. I can maximise and restore windows, but 
not resize them. Even selecting Resize from the window menu does nothing.

How can I get window resizing back?

David King