diff --git a/doc/fixes35.0 b/doc/fixes35.0
index 3217305a2..a49b10eb4 100644
--- a/doc/fixes35.0
+++ b/doc/fixes35.0
@@ -302,6 +302,8 @@ when dipping something in holy/unholy water, only learn its new bless/curse
 	state if hero sees it glow
 describe lit Sunsword as shining rather than glowing
 prevent poly'd shopkeepers from taking on forms that can't handle objects
+attempting to move direction 'u' as a grid bug performed #untrap command;
+	the other diagonals reported "unknown command" instead of "you can't"
 
 
 Platform- and/or Interface-Specific Fixes
diff --git a/include/extern.h b/include/extern.h
index cda31de6e..809c2e400 100644
--- a/include/extern.h
+++ b/include/extern.h
@@ -200,6 +200,7 @@ E void FDECL(show_conduct, (int));
 E int FDECL(xytod, (SCHAR_P,SCHAR_P));
 E void FDECL(dtoxy, (coord *,int));
 E int FDECL(movecmd, (CHAR_P));
+E int NDECL(dxdy_moveok);
 E int FDECL(getdir, (const char *));
 E void NDECL(confdir);
 E const char *FDECL(directionname, (int));
diff --git a/src/cmd.c b/src/cmd.c
index a1499ccaf..fb8a10a51 100644
--- a/src/cmd.c
+++ b/src/cmd.c
@@ -1,4 +1,4 @@
-/*	SCCS Id: @(#)cmd.c	3.5	2008/05/25	*/
+/*	SCCS Id: @(#)cmd.c	3.5	2009/01/28	*/
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -2855,6 +2855,20 @@ register char *cmd;
 	    }
 	}
 
+	if ((do_walk || do_rush) && !context.travel && !dxdy_moveok()) {
+	    /* trying to move diagonally as a grid bug;
+	       this used to be treated by movecmd() as not being
+	       a movement attempt, but that didn't provide for any
+	       feedback and led to strangeness if the key pressed
+	       ('u' in particular) was overloaded for num_pad use */
+	    You_cant("get there from here...");
+	    context.run = 0;
+	    context.nopick = context.forcefight = FALSE;
+	    context.move = context.mv = FALSE;
+	    multi = 0;
+	    return;
+	}
+
 	if (do_walk) {
 	    if (multi) context.mv = TRUE;
 	    domove();
@@ -2968,13 +2982,23 @@ char sym;
 	u.dx = xdir[dp - Cmd.dirchars];
 	u.dy = ydir[dp - Cmd.dirchars];
 	u.dz = zdir[dp - Cmd.dirchars];
+#if 0	/* now handled elsewhere */
 	if (u.dx && u.dy && NODIAG(u.umonnum)) {
 		u.dx = u.dy = 0;
 		return 0;
 	}
+#endif
 	return !u.dz;
 }
 
+/* grid bug handling which used to be in movecmd() */
+int
+dxdy_moveok()
+{
+	if (u.dx && u.dy && NODIAG(u.umonnum)) u.dx = u.dy = 0;
+	return u.dx || u.dy;
+}
+
 /* decide whether a character (user input keystroke) requests screen repaint */
 boolean
 redraw_cmd(c)
@@ -3020,6 +3044,7 @@ getdir(s)
 const char *s;
 {
 	char dirsym;
+	int is_mov;
 
  retry:
 #ifdef REDO
@@ -3042,7 +3067,7 @@ const char *s;
 
 	if (dirsym == '.' || dirsym == 's') {
 	    u.dx = u.dy = u.dz = 0;
-	} else if (!movecmd(dirsym) && !u.dz) {
+	} else if (!(is_mov = movecmd(dirsym)) && !u.dz) {
 	    boolean did_help = FALSE, help_requested;
 
 	    if (!index(quitchars, dirsym)) {
@@ -3056,6 +3081,9 @@ const char *s;
 		if (!did_help) pline("What a strange direction!");
 	    }
 	    return 0;
+	} else if (is_mov && !dxdy_moveok()) {
+	    You_cant("orient yourself that direction.");
+	    return 0;
 	}
 	if (!u.dz && (Stunned || (Confusion && !rn2(5)))) confdir();
 	return 1;
diff --git a/src/dig.c b/src/dig.c
index c565918d0..e69c4ac19 100644
--- a/src/dig.c
+++ b/src/dig.c
@@ -1,4 +1,4 @@
-/*	SCCS Id: @(#)dig.c	3.5	2007/04/02	*/
+/*	SCCS Id: @(#)dig.c	3.5	2009/01/28	*/
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -916,7 +916,7 @@ struct obj *obj;
 	register char *dsp = dirsyms;
 	register int rx, ry;
 	int res = 0;
-	const char *sdp = Cmd.dirchars, *verb;
+	const char *sdp, *verb;
 
 	/* Check tool */
 	if (obj != uwep) {
@@ -934,8 +934,9 @@ struct obj *obj;
 	    return res;
 	}
 
-	while(*sdp) {
+	for (sdp = Cmd.dirchars; *sdp; ++sdp) {
 		(void) movecmd(*sdp);	/* sets u.dx and u.dy and u.dz */
+		if (!u.dz && !dxdy_moveok()) continue;	/* handle NODIAG */
 		rx = u.ux + u.dx;
 		ry = u.uy + u.dy;
 		/* Include down even with axe, so we have at least one direction */
@@ -943,7 +944,6 @@ struct obj *obj;
 		    (u.dz == 0 && isok(rx, ry) &&
 		     dig_typ(obj, rx, ry) != DIGTYP_UNDIGGABLE))
 			*dsp++ = *sdp;
-		sdp++;
 	}
 	*dsp = 0;
 	Sprintf(qbuf, "In what direction do you want to %s? [%s]", verb, dirsyms);