qemu-KVM guest OS occurs many ext3-fs errors after multiple forced shutdown 

Hi:
I met some filesysterm errors in a sles guest on KVM. My system environment is:
HOST: 
   suse 10, the kernel version is 2.6.32.43 
   Qemu-KVM 1.2 
   Libvirt 1.0
guest OS: 
   suse 10, the kernel version is 2.6.32.43
VMs use a qcow2 disk. 

Description of problem:
I have 20+ VMs with qcow2 disk, these VMs have been forced to shut down by
"virsh destroy" many times during and after VM installation.
When these vm reboot,dmesg show a ext3-fs mount error occurred on /usr/local
partion /dev/vda3:
    EXT3-fs warning: mounting fs with errors, running e2fsck is recommendedand
when I wrote into partion /dev/vda3,some errors occurred in dmesg:
1.error (device vda3): ext3_free_blocks: Freeing blocks not in datazone - block
= 1869619311, count = 1error (device vda3): ext3_free_blocks_sb: bit already
cleared for block 2178152error (device vda3): ext3_readdir: bad entry in
directory #1083501: 
2.[347470.661893] attempt to access beyond end of device[347470.661896] vda3:
rw=0, want=6870892952, limit=41945715[347470.661897] EXT3-fs error (device
vda3): ext3_free_branches: Read failure, inode=1083508, block=858861618
3.EXT3-fs error (device vda3): ext3_new_block: block(4295028581) >= blocks
count(-1) - block_group = 1, es == ffff88021b6c7400

I suspect this fs-error is caused by multiple forced shutdown, but I can't
reproduce this bug now.

Could anyone has an idea or suggestion to help me? 

Thanks in Advance
Regards
Ben 

Reproducible: Always

Steps to Reproduce:
I can't reproduce this bug now.


additional:
1.multiple forced shutdown during and after the vm installing
2.vm with qcow2 disk
3.different vm dmesg different errors in above error list(1/2/3)