AJAX :: MaskedEditExtender Cursor Positioning Behavior For Mouse Click Different In IE

I have a 'MaskedEditExtender' textbox for phone number on my application. On IE, when someone clicks somewhere in the middle of the textbox using the mouse, on the first click the cursor is actually placed at the first digit of the number. On the next click positions it is at the mouse position. However, on other browsers like Chrome, Firefox, etc.. on the first click of the mouse, the cursor position is at the mouse position (not at the first digit of the number). There does not seem to be any special code written to specify this behaviour. Is there a default behaviour for 'MaskedEditExtender' on IE which results in this?