Problem with corrupted file on raidz.

[Peter Ankerstål]

Hi, I have a newly installed 3 disk raidz but I just got this:

# uname -a
FreeBSD torus 9.0-RELEASE FreeBSD 9.0-RELEASE #0: Tue Jan  3 07:46:30 UTC 2012     root at farrell.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  amd64

# zpool status -v
pool: store
state: ONLINE
status: One or more devices has experienced an error resulting in data
	corruption.  Applications may be affected.
action: Restore the file in question if possible.  Otherwise restore the
	entire pool from backup.
 see: http://www.sun.com/msg/ZFS-8000-8A
scan: scrub repaired 0 in 1h50m with 0 errors on Tue Mar 13 23:02:53 2012
config:

	NAME        STATE     READ WRITE CKSUM
	store       ONLINE       0     0     0
	  raidz1-0  ONLINE       0     0     0
	    ada0    ONLINE       0     0     0
	    ada1    ONLINE       0     0     0
	    ada2    ONLINE       0     0     0

errors: Permanent errors have been detected in the following files:

      <0x7e>:<0x1f3>


The <0x7e>:<0x1f3> was store/backup:somefile but then I first removed the file and <0x1f3> appeared and then I removed
the whole zfs filesystem and the <0x7e> appeared.. 

First of all, how could I get this type of error when I have a redundant disk setup, also it doesn't show any checksum errors. And second, is there a way to clear this error? After all only one file was affected and is now removed. Actually the whole filesystem is removed.