<igEditors:XamDateTimeEditor x:Name="m_Birthdate"
                                         DisplayMode="IncludeBoth"
                                         MinWidth="125"
                                         Margin="0,0,0,0"
                                         Value="{Binding Birthdate}"
                                         VerticalAlignment="Top"
                                         Mask="yyyy/mm/dd"
                                         AllowShiftingAcrossSections="False"
                                         InvalidValueBehavior="RevertValue"
                                         ClipMode="IncludeBoth">
           <igEditors:XamDateTimeEditor.ValueConstraint>
                      <igEditors:ValueConstraint MinInclusive="1900/01/01"
                                                          MaxInclusive="2100/01/01" />
           </igEditors:XamDateTimeEditor.ValueConstraint>
</igEditors:XamDateTimeEditor>

Unfortunately, the drop down stops responding correctly. When I repeated click on the month/year title to zoom out to "century" view the two correct centuries are shown: 1900-1999 and 2000-2099. However, the later is "grey" to indicate that it takes you to the next page (which it obviously can't). Clicking on 2000-2099 simply closes the drop down.

Furthermore, clicking on 1900-1999 works, but then moving over and clicking on say 2000-2010 also closes the drop down. When I remove the value constraint the correct zoom out/in behavior is back, but of course it now accepts any date.

I'd really appreciate any help.

Thank you in advance,

Robert