Clear doesn't actually clear

[lorenzoPrimi]

Hi,
I recently have a problem with this component, I have a ACEDrawingView over an UIImageView
initialized with simple parameters

    self.signatureView.delegate = self;
    self.signatureView.lineWidth = 2.0f;

but when I call
[self.signatureView clear];
doesn't clear the view, only does it the second time I call the clear function.
What can be the cause of this?

[lorenzoPrimi]

UPDATE: the first clear seems to do something, in fact if I clear once and draw a line on the old one, the old one vanishes.

[lorenzoPrimi]

Updating to 2.2.1 fixed the issue