can I suppress Opera users tooltips? they're covering mine up...

Opera 'tooltips' are popping up and covering some tooltips I'm trying to
use in my left-side nav menu

for eg, see this "test run" menu, left side of this page
http://machines.50webs.com/menutest/

I realize I can "offset" my tooltips further, so mine are 'rightward' of
Opera's tooltips, but I'd rather not....is there a way I can "code in"
in my pages a way of 'supressing' Opera's tooltips? or any other way to
'work around' this, so Opera users aren't "snowed in" with tooltips?

thanks for ideas :-)

toolie