Picture Control changed visibility after changed focus

[venkat raghvan]

Here I am working on MFC dialogue based application,in which there are multiple child dialogues added in tab control;In one child dialogue there are multiple picture controls and I changed bitmap image dynamically on button clicked event,whenever I clicked one of the picture controls and switched to another tab(for Testing purpose)and coming back to current picture control tab that time all controls(which I've clicked previous time)are invisible!!!
How that change occurred and how to solve that problem???