kmail config filters not opening
 

hi,
I am using kmail to receive my mails or send mails. I am using filters too
(by right click on the mail -> create filter-> filter on from) or (settings tab -> configure filters)

but suddenly from few days when i am trying to use them it is failing to open. that means . if I right click on mail -> create filter -> 'filter on from' then the kmail window is suddenly closing instead of open the filter window.

even when I am trying to open the config filters from settings also the same thing happening( kmail window is closing instead of open the filter window)..

can you please help me. i tried to take backup and restored it. then the filter is working but after some time the same problem arises.. what can I do to clear this problem .....