A Question about an activity done by OnTimer()

[ge6a93]

Hello, i have a question about OnTimer() function in Visual C++ 6.0. My program contais 2 classes - let's say a class A and a class B . Class A calls me a screen and the user must choose an option(e.g. Start or something). When the user clicks on START it calls me class B. I'm doing that using DoModal().
In class B i'm using OnTimer() to make moving objects(e.g. ellipses). If i press Esc key it calls me A class back. If i do this process several times(from A class to B and from B to A) i notice that in B class the moving objects start to lag(the falling speed decreases - bug or something). I'm asking for your opinion and solution if you have that. Thanks in advance!