Spinning progress indicator troubles, ugh

gistfile1.m

#import "ZGAppDelegate.h"

@interface ZGAppDelegate ()

@property (nonatomic) NSTimer *timer;
@property (assign) IBOutlet NSProgressIndicator *progressIndicator;

@end

@implementation ZGAppDelegate

// Progress indicator starts out as determinate in IB
// Display when stopped is unchecked
// Auto layout is on
// Three buttons - deterministic, indeterminstic, stop
// See https://dl.dropboxusercontent.com/u/10108199/deterministic.mov for the glitch in action

- (void)animate
{
	[self.progressIndicator incrementBy:1];
}

- (IBAction)makeDeterminate:(id)sender
{
	[self.progressIndicator setHidden:NO];
	[self.progressIndicator setIndeterminate:NO];
	
	self.progressIndicator.minValue = 0;
	self.progressIndicator.doubleValue = 0;
	self.progressIndicator.maxValue = 10;
	
	self.timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(animate) userInfo:nil repeats:YES];
}

- (IBAction)makeIndeterminate:(id)sender
{
	[self.progressIndicator setHidden:NO];
	[self.progressIndicator setIndeterminate:YES];
	[self.progressIndicator startAnimation:self];
}

- (IBAction)stopProgressIndicator:(id)sender
{
	if (self.progressIndicator.isIndeterminate)
	{
		[self.progressIndicator stopAnimation:self];
	}
	else
	{
		[self.timer invalidate];
		self.timer = nil;
	}
	[self.progressIndicator setHidden:YES]; // If I comment this line out and don't hide the indicator, I don't run into the glitch
}

@end