mscomm32.ocx question

I am using in my application mscomm32.ocx - which is a Microsoft Communication control. I work in Windows NT - and with TASK MANAGER I see that, the application leak memory - all the memory which it reads from the serial bus.
Simply I use devices with a big flow of data, and see that each hour the memory application, use the control, larged in 1 MB.
It happens not only in my application, it happens only in the examples "vbterm.exe" and "vcterm.exe" which I got from the MSDN.
Does somebody know, if it is a Microsoft Known Bug, Or it is not bug at all and it can be repaired and how.
Thank.