Disable alt + mouse click in Gnome?

[Dave M G]

Ubuntu Users,

I am running Photoshop 7 under Wine in Ubuntu Feisty. A number of 
functions are accessed by holding the alt button down while clicking the 
mouse.

However, in Gnome (or Nautilus, or Ubuntu), holding the alt button down 
and then clicking the left mouse button makes the mouse cursor turn to a 
hand, and with it one can move the application window around on the 
desktop. This function takes precedence over the application's use of 
the alt key, so I can't access the Photoshop functions.

I looked in System->Preferences->Keyboard Shortcuts, and I disabled all 
the alt functions (since I never use it for navigating around the 
desktop anyway). I did so by selecting the function and clicking 
"Backspace", which seemed to remove it (maybe it didn't?).

However, alt+[mouse click] still moves the application window.

How can I disable this?

Thank you for any advice.

-- 
Dave M G
Ubuntu 7.04 Feisty Fawn
Kernel 2.6.20-15-generic
Pentium D Dual Core Processor