possible ext4 race situation freezing linux

Kernel version: 2.26.28.7
efs2progs version: 1.41.4
arch: x86_64 (amd)

I made this test four times and the results  were the same: linux
freezes and becomes unresponsive. Only solution is to reset the box. I
do not know if the problem is with the USB devices sub-subsystem or a
possible ext4 race condition.

That's the scenario:
1. a vg group (VGSTORE) using usb mass storage devices
2. a non-lvm controlled usb mass storage device named ANDREAS
3. a cpio operation running from the ANDREAS device to a VGSTORE.LV
filesystem  (LV1)
4. a cpio operation from a VGSTORE.LV filesystem (LV2) to LV1
5. a rm operation on LV1

Nothing is recorded in /var/log/messages

I know that this is not too much information but I'm keen to repeat the
tests and turn on any debug options necessary to track the problem.

-- Berendsen