When hiding a TabPanel by setting the Enabled property to false, any validation controls on that panel are still enabled. This is not what I expected, as with other types of panels, the Enabled property usually cascades down. Of course this results in validation errors displayed for hidden tabs.
I am now using the following (clumsy) work around to disable tabs:
public static void DisableTab(TabPanel panel)
panel.Enabled = false;
//work around TabPanel bug and disable the validation controls
private static void DisableValidationControls(Control c)
foreach (Control child in c.Controls)
if (child is BaseValidator)
((BaseValidator)child).Enabled = false;
Lets hope that the quality of the control toolkit gets improved soon.