panic: runtime error: index out of range

[kenneth]

go version
go version go1.4 darwin/amd64

panic: runtime error: index out of range
goroutine 18 [running]:
memcache.(*ManualScheduler).try_reward(0xc208084d00)
/Users/kenneth/beanseye/src/memcache/schedule.go:244 +0x905
memcache.func·009()
/Users/kenneth/beanseye/src/memcache/schedule.go:208 +0x34
created by memcache.NewManualScheduler
/Users/kenneth/beanseye/src/memcache/schedule.go:211 +0x9b3

goroutine 1 [runnable]:
main.main()
/Users/kenneth/beanseye/src/proxy/proxy.go:540 +0x1538

goroutine 6 [syscall]:
os/signal.loop()
/usr/local/Cellar/go/1.4/libexec/src/os/signal/signal_unix.go:21 +0x1f
created by os/signal.init·1
/usr/local/Cellar/go/1.4/libexec/src/os/signal/signal_unix.go:27 +0x35

goroutine 7 [chan receive]:
cmem.func·001()
/Users/kenneth/beanseye/src/cmem/cmem.go:15 +0x4a
created by cmem.init·1
/Users/kenneth/beanseye/src/cmem/cmem.go:18 +0x5c

goroutine 14 [runnable]:
main.update_stats(0xc20801f940, 0x2, 0x2, 0x0, 0x0, 0x0, 0xc2080c6390, 0x2, 0x2, 0x1)
/Users/kenneth/beanseye/src/proxy/proxy.go:166 +0x97
created by main.main
/Users/kenneth/beanseye/src/proxy/proxy.go:458 +0x1ee3

goroutine 15 [runnable]:
main.update_stats(0xc20802b160, 0x1, 0x1, 0x0, 0x0, 0x0, 0xc208056330, 0x1, 0x1, 0x0)
/Users/kenneth/beanseye/src/proxy/proxy.go:166
created by main.main
/Users/kenneth/beanseye/src/proxy/proxy.go:462 +0x1fc8

goroutine 16 [runnable]:
main.func·005()
/Users/kenneth/beanseye/src/proxy/proxy.go:471 +0xb7
created by main.main
/Users/kenneth/beanseye/src/proxy/proxy.go:478 +0x21c0

goroutine 17 [runnable]:
memcache.(*ManualScheduler).procFeedback(0xc208084d00)
/Users/kenneth/beanseye/src/memcache/schedule.go:276
created by memcache.NewManualScheduler
/Users/kenneth/beanseye/src/memcache/schedule.go:205 +0x95e