Sieve: Vacation not working

[Garry]

I have a SuSE Enterprise 10 system set up, which is running smoothly ...
I have Cyrus 2.2.12 on it, which too is working fine - IMAP, SASL-Auth,
the whole 9 yards ... even Sieve itself is fine, messages are moved to
the appropriate folders as directed in the Sieve config ...

Here's an excerpt from the Sieve script:

require [ "vacation" , "fileinto" ] ;

## Flag: |UniqueId:1|Rulename: SpamMsg
if header :contains "From" "gkg"
{
    fileinto "INBOX.Spam" ;
}

## Flag: vacation|UniqueId:0|Rulename: Abwesenheitsbenachrichtigung
if true
{
    vacation :days 7 :addresses [ "admin at ox6.mydomain.de" ,
"admin at mydomain.de" ] :subject "Ich bin nicht da ..." "blah" ;
}


The message is received, but according to /var/log/messages, nothing
happens apart from it being stored locally ...

I'm somewhat at a loss as to where else I can check for the reason of it
not working ... couldn't find anything on Google that would have been
helpful, either ... maybe somebody could point me in the right direction
... ?!

Tnx, -garry