Mousing over the View->View Palette window feels laggy because of how infrequently the palette number indicator left of the OK button is redrawn.
Lowering this rvalue in gui.cpp makes it more responsive:
Code:// Not perfect, but beats using 100% of CPU. // The above may miss things, so draw at least a few times a second. if (num_idle_frames++ == 15) { should_draw = 1; }