This seems to happen for when on particular web sites... how ever I came across a mac owners suggested solution.
Apparently if the mac is made to 'always start up in 32 bit' it goes away...and the described way is to do this:
In Finder "right" click on 'system preferences', click 'Get Info', change to 'Always start in 32 bit'.
However if I Right click on 'System Preferences' ..I get the same as a left click..ie system prefs display.
(Usng snow leopard on an iMac 5,1)
Apparently if the mac is made to 'always start up in 32 bit' it goes away...and the described way is to do this:
In Finder "right" click on 'system preferences', click 'Get Info', change to 'Always start in 32 bit'.
However if I Right click on 'System Preferences' ..I get the same as a left click..ie system prefs display.
(Usng snow leopard on an iMac 5,1)