lost output from SetWindowText

I have an MFC dialog app with several Text controls. All but controls get filled in with UpdateData at dialog initialization via calls like: DDX_Control(pDX, IDC_MY_STATIC, MyText ); . Next, the user checkmarks a checkbox and the ON_ function for the checkbox gets control, running several functions. One of those functions has a loop that invokes MyText.SetWindowText(somestring) followed by multiple sequential calls to CreateProcess each followed by a WaitForSingleProcess. MyText is a CStatic field attached to the control. Here is the problem: I get the output of the first and last SetWindowText calls, but nothing in between. The created processes take about 2 minutes to run, so there should be sufficient time to see the text in my dialog window.