Strrange behavior using masked edit

I have simple Windows form (not WEB app), a test app for this problem.  It has a masked Edit and a button.  mask is "00000000" (8 zeroes) and prompt char is a space, because I don't want a prompt char.  In button click event, I set the focus to the text box because in my real app depending on what the user enters, I do not close my dialog and instead force them to reenter data.   I can click the button all day and all is fine - textbox get focus.  However, if I use the mouse to click in the text box, I get 8 space (size of the mask) inserted into the text box.   Why? I don't get it??  See image.  I can tell this happens by seeing  the blinking cursor.  

spaces in textbox.
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HLRosenbergerAuthor Commented:
oh, I get this behavior even without the button click.  Just clicking into the textbox, and I get the 8 spaces.
HLRosenbergerAuthor Commented:
If I do this in the click event for the textbox, the cursor to the beginning of the text box, and now I can type into it.  Otherwise, with those spaces, I can't type.  

  MaskedTextBox1.Text = ""
Éric MoreauSenior .Net ConsultantCommented:
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AndyAinscowFreelance programmer / ConsultantCommented:
>>mask is "00000000" (8 zeroes) and prompt char is a space

Why are you surprised that it works as you instructed it to work ??
HLRosenbergerAuthor Commented:
Not surprised, really I guess.  I guess there's not way to truly have no prompt character.
AndyAinscowFreelance programmer / ConsultantCommented:
>> I guess there's not way to truly have no prompt character.
Correct (for a masked edit control), for none then you have to code your own, which isn't that difficult for just an integer number.

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HLRosenbergerAuthor Commented:
yup, I'll do it myself in code. thanks.
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