Double faults on bento

Bento (SMP machine running -current) regularly gets a variation of the
following while under load:

Fatal double fault:
eip = 0xc03060c0
esp = 0xe329f00c
ebp = 0xe329f054
cpuid = 1; lapic.id = 00000000
panic: double fault
cpuid = 1; lapic.id = 00000000
Debugger("panic")

Fatal double fault:
eip = 0xc0305d40
esp = 0xe2e34000
ebp = 0xe2e3408c
cpuid = 0; lapic.id = 01000000
panic: double fault
cpuid = 0; lapic.id = 01000000
Debugger("panic")

Running addr2line on the eip values above shows:

bento# addr2line -e kernel.debug 0xc03060c0
/usr/src/sys/i386/i386/machdep.c:2229
bento# addr2line -e kernel.debug 0xc0305d40
/usr/src/sys/i386/i386/machdep.c:2054

Does this suggest anything to anyone?

Kris