I would like to report a bug fix in ns2 2.34 .The file name is ~/ns-allinone-2.34/ns-2.34/wpan/p802_15_4phy.cc. Few lines of code have been inserted to overcome crashes in ns2 while running the multi-hop simulation for an IEEE 802.15.4 network. With these fixes the simulator no longer crashes.
The changes have been made from line 712 onwards. Search for the comment entry "2.34 change" to go to the respective changes