Fix initial bar calculation.

After calculating i (offset in list to top of window), if it's less
than zero, apply it to bar and set i = 0.

Fixes #218

src/uifc/uifc32.c

@@ -928,6 +928,10 @@ int ulist(int mode, int left, int top, int width, int *cur, int *bar
 			if((*bar)<0)
 				(*bar)=0;
 			i=(*cur)-(*bar);
+			if (i < 0) {
+				*bar += i;
+				i = 0;
+			}
 			if(i+(height-vbrdrsize-1)>=opts) {
 				(*bar)=(height-vbrdrsize);
 				if (*bar > *cur)