altmark(a)de.ibm.com writes: Yes, but you need to start somewhere :-) Now we only need to find out the real problem :-). Could you put a breakpoint in this code from window.c if (INTP (Vwindow_pixel_scroll_increment)) fheight = XINT (Vwindow_pixel_scroll_increment); else if (!NILP (Vwindow_pixel_scroll_increment)) default_face_height_and_width (window, &fheight, &fwidth); [I am particularly interested in the value of fheight at this point. I have a feeling it might be 0 (which is really bad, in that case please single step in to default_face_height_and_width to see where the 0 is coming from)] if (Dynarr_length (dla) >= 1) modeline = Dynarr_atp (dla, 0)->modeline; dl = Dynarr_atp (dla, modeline); if (value > 0) { /* Go for partial display line scrolling. This just means bumping the clip by a reasonable amount and redisplaying, everything else remains unchanged. */ if (!NILP (Vwindow_pixel_scroll_increment) && Dynarr_length (dla) >= (1 + modeline) && (dl->ascent - dl->top_clip) - fheight * value > 0) { WINDOW_TEXT_TOP_CLIP (w) += value * fheight; MARK_WINDOWS_CHANGED (w); [Your XEmacs is probably not scrolling because this if statement is true. Could you please find out why (fheight == 0 is the only reason I can think of).] Jan