Window UI is not displaying correctly if using checkbox to display/ hide additional ui(s)

[likage]

I have this UI using maya commands in which I am having problem with one of the checkbox.

Here is the code:

WINID = "mineUI"

def ui():

    # Make sure that the UI isn"t already active

    if cmds.window(WINID, exists=True):

        cmds.deleteUI(WINID)

    cmds.window(WINID, title="My window testing", width=365, height=135,

                sizeable=False)

    # Add a Layout

    cmds.columnLayout(adjustableColumn=True)

    cmds.rowColumnLayout(numberOfColumns=3, columnAttach=[1, "right", 0],

                         columnWidth=[2, 250])

    # Add text field for character to constraint

    cmds.text(label="Constraint From: ")

    constraint_from = cmds.textField("constraint_from")

    cmds.button(label=" <<< ")

    # Add text field for constraint_to

    cmds.text(label="Constraint To: ")

    constraint_to = cmds.textField("constraint_to")

    cmds.button(label=" <<< ")

    # Add checkbox for constraint offset

    cmds.text(label="")

    cmds.checkBox("offset", label="Maintain offset", value=False)

    cmds.text(label="")

    # Add checkbox for time

    cmds.text(label="")

    cmds.checkBox("time", label="Specify frame range", value=False,

                  changeCommand=_frame_range)

    cmds.text(label="")

    # Add labels for frame range

    cmds.text("start", label=" Start Frame ", visible=False, height=1, width=1)

    cmds.textField("start_frame", visible=False, height=1, width=1)

    cmds.text("space1", label="", visible=False, height=1, width=1)

    # Add text field for frame range

    cmds.text("end", label=" End Frame ", visible=False, height=1, width=1)

    cmds.textField("end_frame", visible=False, height=1, width=1)

    cmds.text("space2", label="", visible=False, height=1, width=1)

    # Add button for select all the controls

    cmds.text(label="")

    cmds.button(label=" Select all controls to constraint ")

    cmds.text(label="")

    # Fill first column

    cmds.text(label="")

    cmds.button(label=" Constraint and Bake ")

    cmds.text(label="")

    # Display the window.

    cmds.showWindow(WINID)

def _frame_range(*args):

    switch = cmds.checkBox("time", value=True, query=True)

    if switch:

        # Labels

        cmds.text("start", edit=True, visible=True, height=20, width=65)

        cmds.text("end", edit=True, visible=True, height=20, width=65)

        # Text Fields

        cmds.textField("start_frame", edit=True, visible=True, height=20,

                       width=250)

        cmds.textField("end_frame", edit=True, visible=True, height=20,

                       width=250)

        # Fix Window size

        # This line is not here in my initial code.

        cmds.window(WINID, edit=True, resizeToFitChildren=True)

    else:

        # Labels

        cmds.text("start", edit=True, visible=False, height=1, width=1)

        cmds.text("end", edit=True, visible=False, height=1, width=1)

        # Text Fields

        cmds.textField("start_frame", edit=True, visible=False, height=1,

                       width=1)

        cmds.textField("end_frame", edit=True, visible=False, height=1, width=1)

        # Fix Window size

        cmds.window(WINID, edit=True, width=365)

        cmds.window(WINID, edit=True, height=135)

ui()

If the "Specify frame range" is checked, it will displays the text field boxes etc correctly. However if you uncheck and checked it again, you will notice that the 2 buttons, namely "Select all controls to constraint" and "Constraint and Bake" are somewhat hidden.

But if you re-click on the Window Title, it seems to "expand" the window and displays it correctly.

My question here would be - Are there any other ways in which I can make the window to display correctly (checked, unchecked and checked the frame range checkbox)?