Update: booted 10.04 Beta1 with nomodeset parameter.
Pressing Fn+F3 decreases volume. (keyboard icon for Fn+F3 suggests "mute") Pressing Fn+F4 increases volume. (keyboard icon for Fn+F4 suggests "change volume") Pressing Fn+F5 decreases brightness (keyboard icon for Fn+F5 suggests "change brightness") Pressing Fn+F6 increases brightness (F6 has no Fn function marking).
Laptop is Sony Vaio PCG-R505EL.
Update: booted 10.04 Beta1 with nomodeset parameter.
Pressing Fn+F3 decreases volume. (keyboard icon for Fn+F3 suggests "mute")
Pressing Fn+F4 increases volume. (keyboard icon for Fn+F4 suggests "change volume")
Pressing Fn+F5 decreases brightness (keyboard icon for Fn+F5 suggests "change brightness")
Pressing Fn+F6 increases brightness (F6 has no Fn function marking).
Laptop is Sony Vaio PCG-R505EL.