I am trying to run a deterministic VI (LV 7.0) which reads data from a DSP and displays it in a graph. The VI has to read the data within a certain time or the DSP overwrites the buffer. I find that the graph stops reading (for about .25 sec) when I click on its title bar (or that of any other VI), and I lose data. The graph is running in the Data Acquisition thread, under Time Critical Priority (the only VI in this thread and with this priority). I have tried a dual 2400 CPU (AMD) under WinXP Pro, and also a PIII-1000 single CPU under Win2000. Same result. I have also tried a bus mouse (USB and PS2) and a serial mouse (COM1) - same result. Under LabVIEWs Tools/Options, I have "Run With Multiple Threads" checked. How can I ensure that the mouse (or keyboard, for that matter) does not stop my graph VI?