diff --git a/Changes b/Changes
index 29b8f53c2..9ac365e5a 100644
--- a/Changes
+++ b/Changes
@@ -2605,3 +2605,6 @@ seen. gmtime warning still there
   (#0001365)
 - Fixed a bug with SVSNLINE - reported by FreakyComputer and fixed by AngryWolf 
   (#0001399)
+- example.conf: added +i in modes-on-connect.
+- Temporarely added fdlist debugcode, please report any bugreports it gives,
+  it would especially be helpful if you know _what_ triggered the error :).
diff --git a/doc/example.conf b/doc/example.conf
index 4265e8862..3aa5f87ad 100644
--- a/doc/example.conf
+++ b/doc/example.conf
@@ -701,7 +701,7 @@ set {
 
 set {
 	kline-address "set.this.email";
-	modes-on-connect "+xw";
+	modes-on-connect "+ixw";
 	modes-on-oper	 "+xwgs";
 	oper-auto-join "#opers";
 	dns {
diff --git a/src/fdlist.c b/src/fdlist.c
index 38e21dbbc..7a27aec7a 100644
--- a/src/fdlist.c
+++ b/src/fdlist.c
@@ -33,9 +33,14 @@ extern fdlist busycli_fdlist;
 extern fdlist serv_fdlist;
 extern fdlist oper_fdlist;
 
+#define FDLIST_DEBUG
+
 void addto_fdlist(int fd, fdlist * listp)
 {
 	int  index;
+#ifdef FDLIST_DEBUG
+	int i;
+#endif
 
 	/* I prefer this little 5-cpu-cycles-check over memory corruption. -- Syzop */
 	if ((fd < 0) || (fd >= MAXCONNECTIONS))
@@ -49,6 +54,21 @@ void addto_fdlist(int fd, fdlist * listp)
 		return;
 	}
 
+#ifdef FDLIST_DEBUG
+	for (i = listp->last_entry; i; i--)
+	{
+		if (listp->entry[i] == fd)
+		{
+			char buf[2048];
+			ircsprintf(buf, "[BUG] addto_fdlist() called for duplicate entry! fd=%d, fdlist=%p, client=%s (%p/%p/%p/%p)",
+				fd, listp, local[fd] ? local[fd]->name : "<null>", &default_fdlist, &busycli_fdlist, &serv_fdlist, &oper_fdlist);
+			sendto_realops("%s", buf);
+			ircd_log(LOG_ERROR, "%s", buf);
+			return;
+		}
+	}
+#endif
+
 	if ((index = ++listp->last_entry) >= MAXCONNECTIONS)
 	{
 		/*
@@ -66,6 +86,9 @@ void addto_fdlist(int fd, fdlist * listp)
 void delfrom_fdlist(int fd, fdlist * listp)
 {
 	int  i;
+#ifdef FDLIST_DEBUG
+	int cnt = 0;
+#endif
 
 	/* I prefer this little 5-cpu-cycles-check over memory corruption. -- Syzop */
 	if ((fd < 0) || (fd >= MAXCONNECTIONS))
@@ -79,6 +102,24 @@ void delfrom_fdlist(int fd, fdlist * listp)
 		return;
 	}
 
+#ifdef FDLIST_DEBUG
+	for (i = listp->last_entry; i; i--)
+	{
+		if (listp->entry[i] == fd)
+			cnt++;
+	}
+	if (cnt > 1)
+	{
+		char buf[2048];
+		ircsprintf(buf, "[BUG] delfrom_fdlist() called, duplicate entries detected! fd=%d, fdlist=%p, client=%s (%p/%p/%p/%p)",
+			fd, listp, local[fd] ? local[fd]->name : "<null>", &default_fdlist, &busycli_fdlist, &serv_fdlist, &oper_fdlist);
+		sendto_realops("%s", buf);
+		ircd_log(LOG_ERROR, "%s", buf);
+		return;
+	}
+#endif
+
+
 	for (i = listp->last_entry; i; i--)
 	{
 		if (listp->entry[i] == fd)
diff --git a/src/s_misc.c b/src/s_misc.c
index 13db7f4a7..713d82867 100644
--- a/src/s_misc.c
+++ b/src/s_misc.c
@@ -385,6 +385,29 @@ int  exit_client(aClient *cptr, aClient *sptr, aClient *from, char *comment)
 	if (MyConnect(sptr))
 	{
 #ifndef NO_FDLIST
+#define FDLIST_DEBUG
+#ifdef FDLIST_DEBUG
+		{
+			int i;
+			int cnt = 0;
+			
+			if (!IsAnOper(sptr))
+			{
+				for (i = oper_fdlist.last_entry; i; i--)
+				{
+					if (oper_fdlist.entry[i] == sptr->slot)
+					{
+						sendto_realops("[BUG] exit_client: oper_fdlist entry while not oper, fd=%d, user='%s'",
+							sptr->slot, sptr->name);
+						ircd_log(LOG_ERROR, "[BUG] exit_client: oper_fdlist entry while not oper, fd=%d, user='%s'",
+							sptr->slot, sptr->name);
+						delfrom_fdlist(sptr->slot, &oper_fdlist); /* be kind of enough to fix the problem.. */
+						break; /* MUST break here */
+					}
+				}
+			}
+		}
+#endif
 		if (IsAnOper(sptr))
 			delfrom_fdlist(sptr->slot, &oper_fdlist);
 		if (IsServer(sptr))