>oReindex = createobject('frmReindex', 'X_TAGDBF', 'DBF_NAME', 'TAG_NAME', 'KEY_NAME')
>oReindex.show()
>
>If the .WINDOWTYPE property is set to MODAL everything works fine. If it is
>set to MODELESS, the screen flashes on the screen and then is gone.

If I'm correct, your form leaves the screen as soon as oReindex goes out of scope. The quick and dirty way would be to bind it to a Public variable: you could also write a loop in the procedure above, after the .Show(), which sat and waited for your form to go away before exiting.