Hi PJM
I have experienced a similar problem that occurs from time to time. After this has happend a few times I tried to figure out what was happening and by coincidense I noticed that after a minimize followed by maximize of the LabVIEW front panel the problem dissapeared!?? And for the record the problem is even there when the VI has stopped and I am working in the diagram. (Here you will notice a slow reaction to mouse clicks).
Looking in the task manager showed that the LV process was using all the CPU power. I have also opened the Process Explorer and tried to find out what LV was dooing but I could not find anything. It all looked normal (port access, disk access, memory usage, TCP comm ...).
I think these problems are related to the LabVIEW <-> Windows interface and as one of the guys on info-labview pointed out it seems to be related to which window has the focus in the Windows operating system and the associated priority assigned by Windows. What NI should look into is why this did not happend in LV 7.1.1. on the same operating system.
Regards
Henrik Molsen