Sometimes, if more than one "tool windows" (e.g. Products and Pixel Info) are open and overlapping, they start to flicker. Sometimes this can block any input device (mouse and keyboard) which is anoying. It looks as if VISAT trys to bring an active window in the foreground, but then makes the other window active and so on. I think this could be a problem in the interaction between KDE and Visat. The most simple solution would be to have configurable option for VISAT that disables the "automatic foreground for active windows" feature.