Does Windows Automatically put processes

We have an application that takes data from a serial link and after processing the data transmits data to an external device and then monitors the divice using a Digital I/O card. Once a set of signal are seen the process repeats. If we run this program in the foreground the program stops after several hundred cycles until we move the mouse or press a key. If we run the program in the background with any other program just siiting as foreground the progrma works fine.

Does Windows 2000 automatically put the foreground process into a sleep mode if it sees no activity on the keyboard or mouse over a period?