diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index 35ad3d88ac3..8a9e13902e1 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.200.2.3 2006/11/17 18:00:25 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.200.2.4 2010/07/29 16:15:33 rhaas Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -2740,8 +2740,16 @@ heap_xlog_newpage(XLogRecPtr lsn, XLogRecord *record)
 	Assert(record->xl_len == SizeOfHeapNewpage + BLCKSZ);
 	memcpy(page, (char *) xlrec + SizeOfHeapNewpage, BLCKSZ);
 
-	PageSetLSN(page, lsn);
-	PageSetTLI(page, ThisTimeLineID);
+	/*
+	 * The page may be uninitialized. If so, we can't set the LSN
+	 * and TLI because that would corrupt the page.
+	 */
+	if (!PageIsNew(page))
+	{
+		PageSetLSN(page, lsn);
+		PageSetTLI(page, ThisTimeLineID);
+	}
+
 	LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
 	WriteBuffer(buffer);
 }
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 59c99fc3e1b..8f8d28e825c 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.174.2.10 2010/07/01 14:11:03 rhaas Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.174.2.11 2010/07/29 16:15:33 rhaas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -5893,8 +5893,15 @@ copy_relation_data(Relation rel, SMgrRelation dst)
 
 			recptr = XLogInsert(RM_HEAP_ID, XLOG_HEAP_NEWPAGE, rdata);
 
-			PageSetLSN(page, recptr);
-			PageSetTLI(page, ThisTimeLineID);
+			/*
+			 * The page may be uninitialized. If so, we can't set the LSN
+			 * and TLI because that would corrupt the page.
+			 */
+			if (!PageIsNew(page))
+			{
+				PageSetLSN(page, recptr);
+				PageSetTLI(page, ThisTimeLineID);
+			}
 
 			END_CRIT_SECTION();
 		}