I have an activex command button, "CommandButton1" on Sheet1, which issues
command "UserForm1.Show"; in Userform1 I have a command button, "PrintIt"
with the single line "ActiveWorkbook.Sheets("Chart2").PrintPreview" in the
_click event handler. (The same problem occurs with "printout", but this way
I don't waste the paper.)

What happens is, I get the chart in the preview window, but it's as if there
is a smaller version of the chart on top of a larger version. As I
indicated, if I use "...printout" instead of "...printpreview", it prints
this way, too, i.e., with "2 images" of the chart, a smaller superimposed on
a larger.

The same line, "ActiveWorkbook.Sheets("Chart2").PrintPreview" (or
..PrintOut), when attached directly to a command button on the spreadsheet,
works as expected, with only one image of the chart.

Be warned: if you try this with "PrintPreview", it'll hang up the sheet to
the point that only killing it from taskman will get you out.

here's the code for the button on the spreadsheet that calls printpreview
itself

Private Sub CommandButton2_Click()
ActiveWorkbook.Sheets("Chart2").PrintPreview
End Sub

and here's the code that calls it from the command button on the userform:

Private Sub cbPrintIt_Click()
ActiveWorkbook.Sheets("Chart2").PrintPreview
End Sub

And that's all the code there is in the entire workbook.

Reproduce it yourself, you'll see.