[CentOS] raid resync deleting data?

Hello,

I have a c5 box with a 6 drive raid 6 array.

I was going away over Christmas so I was shutting the machine down,
I noticed a raid resync (on the raid 6 array) so i stopped it,
using the command

#  echo "idle" > /sys/block/md5/md/sync_action

then shut the machine down.

A week later I turned the machine on and started copying data to it
around 24 hours later a raid resync occurred and wiped all the new
data I had copied to it.

To me this seems broken, is it because I manually stopped a previous
resync that it got in this state?

Any ideas?

As for log messages there is nothing in the /var/log/messages file, only

Jan  2 19:38:39 bolivia kernel: md: syncing RAID array md5
Jan  2 19:38:39 bolivia kernel: md: minimum _guaranteed_ reconstruction 
speed: 1000 KB/sec/disc.
Jan  2 19:38:39 bolivia kernel: md: using maximum available idle IO 
bandwidth (but not more than 200000 KB/sec) for reconstruction.


no other errors or anything.

Thanks
Nathan