Screen Flickering!

Hi,
i am on working on the Ticker functionalities, ie to make a Text Scroll. I was successfull on that but the problem arouse when i tested it on the phone.
The Screen Flickers very badly and it settles down after a while.
Is there any way to remove this Flcikering problem.
This is the code which i call in the Draw() to make the text scroll.

    CWindowGc& gc = SystemGc();
    TRect iClipRect(20,175,158,187);    
    gc.SetClippingRect(iClipRect);
    gc.DrawRect(iClipRect);
    const CFont* fp = iEikonEnv->DenseFont();
    gc.UseFont(fp);
    gc.SetPenColor(KRgbBlue);   
    gc.DrawRect(iClipRect);
    gc.DrawText(TickerText,TPoint(ixt,185)); 
    gc.CancelClippingRect();

Please provide me some tips on this.
i came across some threads on Double buffering. Will that help me out in drawing a text without Flickering?

Regards

Priju