A stranger problem in CActive Object

[jerrysdfha]

First,in the method TimerExpired(),I write following codes:
// Timer control, called everytime the time times out
void CMMBoxProgressControl::TimerExpired()
{
iAnimationFrame++;
iTempCount++;
if (iAnimationFrame>=100)
{
iAnimationFrame = 0;
}
TBuf<24> iTempBuf;
iTempBuf.AppendNum(iAnimationFrame);

CWindowGc& gc=SystemGc();
gc.Activate(*DrawableWindow());
gc.Deactivate();

iTimer->After((TTimeIntervalMicroSeconds32)200000);
}

And then this method is called in a CActive periodically.
but every time the frist called by CActive is well, after the first called.the application is crash.

if i use the following codes instead of the above codes using red font. the application is well.

CAknConfirmationNote* iConfirmNote = new (ELeave)CAknConfirmationNote;
iConfirmNote->ExecuteLD(iTempBuf);

who can help me ,thanks in advanced!

[symbianyucca]

just call DrawNow() and let the system handle the drawing into the screen by calling Draw().