In some cases it isn't possible to jump from one control to the next.

Please try the following with the example solution TaskPanel.sln which is shipped with the setup.

In the first taskpanel group are 3 textboxes. If you are putting the cursor in the first textbox you can jump with the TAB key to the next textbox and from the last textbox to the next taskpanel group and so on. At the point from jumping from the last control in a taskpanel group to the first control in the following taskpanel group there is a flaw. If the following taskpanel group is not expanded the cursor is not visible because the control inside the taskpanel group isn't visible. This could be confusing to the user, but it's not an error. But a really error is if an expandable taskpanel group is minimized and then expanded again. In this case is it impossible to reach the controls with the TAB key, it seems this controls are ignored.  And if you are putting the cursor in the first control of this group and you are trying to jump to the next control, it fails because the cursor jumps to the next group.

What is to do to prevent this curios behaviour?