Object invisible when walking

default
{
    state_entry()
    {
        llSetAlpha(1.0, ALL_SIDES);
        llSetTimerEvent(0.2);
    }

    timer()
    {
        if (llGetAgentInfo(llGetOwner()) & AGENT_WALKING)
        {
            state walking;
        }
    }
}
state walking
{
    state_entry()
    {
        llSetTimerEvent(0.2);
        llSetAlpha(0.0, ALL_SIDES);
    }
    timer()
    {
        if (!(llGetAgentInfo(llGetOwner()) & AGENT_WALKING))
        {
            state default;
        }
    }
}