rad tab control dose not show more then 3 tab

Hi,

i have in big trouble & bit confused
I am using telerik rad control inside asp:Panel with old version RadTabStrip.Net2, but when i am clicking 3rd tab the tab control is hide.
MyPage:
------------------------------------------------------------------------------
Panel1     |  Panel2
Grid         |  Tab1 | Tab2 | Tab3 | Tab4
                |
                |

When i am clicking Tab3 the Tab coltrol is hide.

But one think if I change AutoPostBack="false" of RadTabStrip then all the tabs are showing correctly. But I need tab click event also.

Please help me asap.


Thanks
Chandan