I am using VBA in Excel XP with Windows 2000

I have a simple user form on which there is only a single calendar control (v. 10). A button on a sheet displays the form. When the user double clicks the calendar, the date clicked is captured and entered into a cell on the sheet. No problem

PROBLEM: Each time the form is displayed, the form size gets a little bit smaller. Eventually, a portion of the right edge of the calendar control becomes obscured. There is nothing in my code that tells this form to resize

I'm not that familiar with forms, so am I missing something or what? Please help if possible...what's going on

Thanks in advance for your assistance.