IValueConverter.Convert doesn't get called on a OneWay bind

Question

I have a boolean property (that does called INotifyPropertyChanged in the setter) that is bound to a button.IsEnabled property in my XAML. Currently I'm using a TwoWay binding, but this is causing problems and I only need a OneWay binding. My problem is that the converter I'm using doesn't get called beyond the first time the program starts up. I've put breakpoints in the setter and it gets called loads, but the Convert() method doesn't get called at all. Why is this?

Some code:

public bool IsSaving
    {
        get
        {
            return _isSaving;
        }
        set
        {
            _isSaving = value;
            NotifyOfPropertyChange(() => IsSaving);
        }
    }

and the XAML:

IsEnabled="{Binding Path=IsSaving, Mode=OneWay, Converter={StaticResource booleanToNotEnabledConverter}}"

The converter really just returns !(bool)value so the button gets disabled when IsSaving is true.

Answer 1

Some changes at runtime might cause the binding to break (since you bind to the DataContext + a relative path), if you use Visual Studio make sure to check the Output-window for any binding errors.

Edit: Since it has not been noted: That is a stardard binding and there is nothing wrong with the posted code, the problem has to be caused by the context.