diff -uNr orig/iaxclient/lib/libiax2/src/iax.c new/iaxclient/lib/libiax2/src/iax.c
--- orig/iaxclient/lib/libiax2/src/iax.c	2007-10-23 12:53:32.281250000 +0300
+++ new/iaxclient/lib/libiax2/src/iax.c	2007-10-29 16:34:40.812500000 +0200
@@ -3194,7 +3194,20 @@
 				/* It's been acked.  No need to send it.   Destroy the old
 				   frame. If final, destroy the session. */
 				if (frame->final)
-					destroy_session(frame->session);
+					/* sskacar: Quick deallocation and allocation of sessions may result in
+					   the same-address-use ! Therefore we cannot trust remote-sent address only
+					   Best bet is checking by somewhat unique properties to decide 
+					   if we really intend to destroy this session.
+					   Example Case:
+					   - Have a call
+					   - Dump that call and immediately request a new call (or have a incoming call request by a lesser chance)
+					   - By considerable probability, you might get the previous address for the session.
+					   - When execution hits to this point as a result of previous call ending
+					     (as client informs server about dumping and frees the previous session, 
+						   server proccess call-dumping and eventually this point reached)
+					   - frame->session param to the destroy_session() belongs to the new & valid session ! */
+					if (frame->session && (frame->callno == frame->session->callno))
+						destroy_session(frame->session);
 				if (frame->data)
 					free(frame->data);
 				free(frame);