Custom UIButton background image not appearing until tapped - objective-c

Question

In app my, if you tap on a certain area a UIPopoverController appears with UIButtons that perform certain tasks when clicked. The UIButtons (called CableDisconnectButton) are a subclassed UIButton so I could add two additional properties to them. I also add UILabels to go over the buttons
However, the background images of the buttons are invisible or don't appear until I tap on the screen somewhere. The UIlabels show up fine, but not the buttons. It can be a tap on the UIPopoverController or anywhere else on the screen. Once I've tapped that first time, the buttons will be there until the app is closed. So, this only happens right after launch and up until I first open that UIPopover. I tap plenty of times before opening the popover.
The functionality of the buttons and everything else works fine, but the background images are hidden on that first launch and I have no idea why.
Here's how I create the buttons and UILabel:
//create custom button
CableDisconnectButton *removeConnectionButton = [CableDisconnectButton buttonWithType:UIButtonTypeCustom];
removeConnectionButton.frame = CGRectMake(x, y, 190, 80);
removeConnectionButton.backgroundColor = [UIColor clearColor];
[removeConnectionButton setBackgroundImage:[UIImage imageNamed:#"images/cable_disconnect_button.png"] forState:UIControlStateNormal];
[removeConnectionButton setBackgroundImage:[UIImage imageNamed:#"images/cable_disconnect_button_over.png"] forState:UIControlStateHighlighted];
//set input and output jacks to button properties
removeConnectionButton.inputJack = inputJack;
removeConnectionButton.outputJack = self.outputJackView;
//add action to button
[removeConnectionButton addTarget:self action:#selector(removeConnectionButtonTarget:) forControlEvents:UIControlEventTouchUpInside];
//create label for output
UILabel *outputConnectionLabel = [[UILabel alloc] initWithFrame:CGRectMake(x+18, y+5, 180, 22)];
outputConnectionLabel.backgroundColor = [UIColor clearColor];
outputConnectionLabel.textColor = [UIColor whiteColor];
outputConnectionLabel.text = self.outputJackView.jackDisplayName;
outputConnectionLabel.font = [UIFont systemFontOfSize:16];
//add subviews
[self addSubview:removeConnectionButton];
[self addSubview:outputConnectionLabel];
I've tried to add a regular, non-custom UIButton and it appears without the tap. I suspect it may have something to do with the subclassed UIButton, but I'm not sure why. The extra properties added to the UIButton are strings that are crucial to the functionality of the and can't be omitted.

Answer 1

After beating my head off the desk for days, I ran into the "Clean Build Folder" option. I've cleaned the project plenty of times, but wasn't aware of "Clean Build Folder". To execute this, simple hold the Option key, click Product from the menu and select Clean Build Folder.
So, if your app isn't behaving the way it should and it makes no sense AT ALL, try this.