diff --git a/engine/client/cl_ents.c b/engine/client/cl_ents.c
index d535ef20..fcf5116a 100644
--- a/engine/client/cl_ents.c
+++ b/engine/client/cl_ents.c
@@ -598,7 +598,8 @@ void FlushEntityPacket (void)
 
 	memset (&olde, 0, sizeof(olde));
 
-	cl.validsequence = 0;		// can't render a frame
+	if ((cl.validsequence&UPDATE_MASK) == (cls.netchan.incoming_sequence&UPDATE_MASK))
+		cl.validsequence = 0;		// last-known-good sequence is becoming invalid.
 	cl.inframes[cls.netchan.incoming_sequence&UPDATE_MASK].invalid = true;
 
 	// read it all, but ignore it
@@ -1316,36 +1317,18 @@ void CLQW_ParsePacketEntities (qboolean delta)
 		from = MSG_ReadByte ();
 
 //		Con_Printf("%i %i from %i\n", cls.netchan.outgoing_sequence, cls.netchan.incoming_sequence, from);
-
-		oldpacket = cl.inframes[newpacket].delta_sequence;
 		if (cls.demoplayback == DPB_MVD || cls.demoplayback == DPB_EZTV)
 			from = oldpacket = cls.netchan.incoming_sequence - 1;
+		oldpacket = cl.inframes[from & UPDATE_MASK].frameid;
 
-		if (cls.netchan.outgoing_sequence - cls.netchan.incoming_sequence >= UPDATE_BACKUP - 1) {
-			// there are no valid frames left, so drop it
-			FlushEntityPacket ();
-			cl.validsequence = 0;
-			return;
-		}
-
-		if ((from & UPDATE_MASK) != (oldpacket & UPDATE_MASK)) {
-			Con_DPrintf ("WARNING: from mismatch\n");
-//			FlushEntityPacket ();
-//			cl.validsequence = 0;
-//			return;
-		}
-
-		if (cls.netchan.outgoing_sequence - oldpacket >= UPDATE_BACKUP - 1)
+		if (cl.inframes[from&UPDATE_MASK].invalid ||	//old frame is unusable
+			cls.netchan.outgoing_sequence - oldpacket >= UPDATE_BACKUP - 1)	// we must have lost the sequence its trying to delta from (or just too old).
 		{
-			// we can't use this, it is too old
 			FlushEntityPacket ();
-			// don't clear cl.validsequence, so that frames can still be rendered;
-			// it is possible that a fresh packet will be received before
-			// (outgoing_sequence - incoming_sequence) exceeds UPDATE_BACKUP - 1
 			return;
 		}
 
-		oldp = &cl.inframes[oldpacket & UPDATE_MASK].packet_entities;
+		oldp = &cl.inframes[from & UPDATE_MASK].packet_entities;
 		full = false;
 	}
 	else
@@ -1428,7 +1411,7 @@ void CLQW_ParsePacketEntities (qboolean delta)
 				newp->entities = BZ_Realloc(newp->entities, sizeof(entity_state_t)*newp->max_entities);
 			}
 			if (oldindex >= oldp->max_entities)
-					Host_EndGame("Old packet entity too big\n");
+				Host_EndGame("Old packet entity too big\n");
 			newp->entities[newindex] = oldp->entities[oldindex];
 			newindex++;
 			oldindex++;
diff --git a/engine/client/cl_input.c b/engine/client/cl_input.c
index 77784287..f989f8c1 100644
--- a/engine/client/cl_input.c
+++ b/engine/client/cl_input.c
@@ -2096,13 +2096,10 @@ qboolean CLQW_SendCmd (sizebuf_t *buf, qboolean actuallysend)
 	//delta_sequence is the _expected_ previous sequences, so is set before it arrives.
 	if (cl.validsequence && !cl_nodelta.ival && cls.state == ca_active)// && !cls.demorecording)
 	{
-		cl.inframes[cls.netchan.outgoing_sequence&UPDATE_MASK].delta_sequence = cl.validsequence;
 		MSG_WriteByte (buf, clc_delta);
 //		Con_Printf("%i\n", cl.validsequence);
 		MSG_WriteByte (buf, cl.validsequence&255);
 	}
-	else
-		cl.inframes[cls.netchan.outgoing_sequence&UPDATE_MASK].delta_sequence = -1;
 
 	if (cl.sendprespawn || !actuallysend)
 		buf->cursize = st;	//don't send movement commands while we're still supposedly downloading. mvdsv does not like that.
diff --git a/engine/client/client.h b/engine/client/client.h
index 1c3effeb..5085a536 100644
--- a/engine/client/client.h
+++ b/engine/client/client.h
@@ -248,9 +248,6 @@ typedef struct
 
 typedef struct
 {
-	//this is the sequence we requested for this frame.
-	int			delta_sequence;		// sequence number to delta from, -1 = full update
-
 	// received from server
 	int			frameid;		//the sequence number of the frame, so we can easily detect which frames are valid without poking all in advance, etc
 	int			ackframe;		//the outgoing sequence this frame acked (for prediction backlerping).