I started having the strangest crash that only happened when I killed an ant with Boone following me. See http://www.gamesas.com/index.php?/topic/1146342-basincreek-building-crashes-with-boone/ for more on that.

After some troubleshooting figured out what is causing the crash. Earlier in the game I was breaking down every shotgun shell I found and making 20 gauge slugs. When I acquired a 12 gauge hunting shotgun and realized I couldn't break down all of those 20 gauge slugs to make them into 12 gauge slugs, I gave Boone my lever action shotgun and the 20 gauge slugs rather than let them go to waste. I just did the quest where I killed Cook Cook and collected his head for the bounty. I picked up his flamer, incinerator and some flamer fuel. I couldn't carry it all so I dumped it on Boone.

Rather than head straight back to Camp McCarran to collect the bounty, I explored the surrounding area. I found and entered the Basincreek Building, but as soon as I killed an ant, the game crashed. It did it only with the ants, not the radroaches. I left Boone outside and cleared the building out. I then found and entered the Allied Technologies Offices building to the East. There were two giant ants greeting me when I entered, and It would crash as soon as I entered the building with Boone following. Again I made him wait outside while I went in and cleared it out.

Just to the south of the Allied Technologies Offices building is a barn with a couple of giant ants outside of it. If I shot one of them, the game crashed. I didn't even have to kill them, it did it if I just shot them. I know I killed some ants near the Helios power station earlier while Boone was following, so I fast traveled to that area. Once again, I shoot an ant, the game crashed. I found and loaded a save game from earlier in my play right when I got to Helios. I walked North to where the ants were and killed them fine, no crash.

I figured it had to be something in Boone's inventory that he was trying to use that he didn't have back then. He currently has a lever action shotgun, flamer and incinerator. I removed one, shot an ant and repeated until it didn't crash. When I removed the incinerator the game quit crashing. This only happens when I shoot or kill an ant.

Further testing makes things weirder. If I leave everything in Boone's inventory and tell him to use melee weapons, then shoot an ant, he would equip the incinerator and kill the ants, no crash. If I remove all weapons except the incinerator, he equips his hunting rifle and uses it instead, and the game does not crash.

This is the error report from the Windows application event log:

Faulting application name: FalloutNV.exe, version: 1.2.0.285, time stamp: 0x4cd9d70bFaulting module name: FalloutNV.exe, version: 1.2.0.285, time stamp: 0x4cd9d70bException code: 0xc0000005Fault offset: 0x00077affFaulting process id: 0x904Faulting application start time: 0x01cb938a35e83a97Faulting application path: d:\steam\steamapps\common\fallout new vegas\FalloutNV.exeFaulting module path: d:\steam\steamapps\common\fallout new vegas\FalloutNV.exeReport Id: 8abdab40-ff7d-11df-84d7-0026189b8c1f