nsslider subclass not responding to mouseUp:

FROM : Daniel Angermeier
DATE : Mon Jun 05 18:19:47 2006

Hi,

I've subclassed NSSlider and I I want it to perform some additional
things when my custom instance receives mouse down or mouse up events.
so in my .m file of the nsslider subclass I wrote:
-(void)mouseDown:(NSEvent *)theEvent{
    [super mouseDown:theEvent];    // regular behavior of NSSlider
    // some additional behavior
    NSLog(@"mouse down");
}

-(void)mouseUp:(NSEvent *)theEvent{
    [super mouseUp:theEvent];    // regular behavior of NSSlider
    // some additional behavior
    NSLog(@"mouse up");
}

upon mouse down on my custom slider, nothing happens. upon mouse up
"mouse down" is logged.
what am I doing wrong ?

thanks,
daniel