Amd64 dedicated server locking up on vehicle maps

[Clint Goudie-Nice]

This seems to be a recurrant theme on our server. When people play
vehicle based maps, generally Vehicle Invasion, within 2 or 3 maps, the
server hangs with 100% cpu utilization. The only corrective action is to
go to the server console, press ctrl-c at which point I get the app
requested exit message, and then I have to press ctrl-c again... Then I
get this dump...

Developer Backtrace:
[ 1]  ./ucc-bin-linux-amd64 [0x9c53bd]
[ 2]  ./ucc-bin-linux-amd64 [0x9c563c]
[ 3]  /lib64/tls/libpthread.so.0 [0x36fbf0c4a0]
[ 4]  ./ucc-bin-linux-amd64 [0xbafa21]
[ 5]  ./ucc-bin-linux-amd64 [0x8bb49a]
[ 6]  ./ucc-bin-linux-amd64 [0x9725e2]
[ 7]  ./ucc-bin-linux-amd64 [0x8bbb91]
[ 8]  ./ucc-bin-linux-amd64 [0x9282e7]
[ 9]  ./ucc-bin-linux-amd64 [0x9248a6]
[10]  ./ucc-bin-linux-amd64 [0x916821]
[11]  ./ucc-bin-linux-amd64 [0x5b6009]
[12]  ./ucc-bin-linux-amd64 [0x56b786]
[13]  ./ucc-bin-linux-amd64 [0x53498a]
[14]  ./ucc-bin-linux-amd64(atan+0x26bf) [0x40630f]
[15]  /lib64/tls/libc.so.6(__libc_start_main+0xf2) [0x36fb01c072]
[16]  ./ucc-bin-linux-amd64(strcat+0xaa) [0x403e2a]
Unreal Call Stack: AONSHoverCraft::UpdateVehicle <-
ASVehicle::execUpdateVehicle <- UObject::ProcessEvent <-
ASVehicle::preKarmaStep <- CallPreBodyStep <- ProcessPartitions <-
KWorldStepSafeTime <- KTickLevelKarma <- TickAllActors <- ULevel::Tick
<- TickLevel <- UGameEngine::Tick <- UpdateWorld <-
UServerCommandlet::Main
Exiting.
FileManager: Reading 0 GByte 395 MByte 514 KByte 777 Bytes from HD took
9.104828
 seconds (3.874906 reading, 5.229922 seeking).
FileManager: 0.000000 seconds spent with misc. duties
Name subsystem shut down
Allocation checking disabled