Help: Setup SPAM Filters

[makan]

hi all,

i got an error message when i tried to add/delete SPAM Filters on my1st-domain.com

When i add a filter it said:
-----------------------------
Created...
A filter has been added that blocks all mail header_subject: that is xxx
Fatal! Write Failure: /etc/vfilters/my2nd-domain.net. Ignore any messages of success this can only result in failure!

When i delete a filter it said:
--------------------------------
$header_subject: is "xxx" has been deleted.
Fatal! Write Failure: /etc/vfilters/my2nd-domain.net. Ignore any messages of success this can only result in failure!

any body know why????