multi select validation from file

I've been trying to get a multi select DD property to work with  
validation info coming from a file. I have a file called validate.txt  
living in my site root folder and it's read fine but when I select any  
of the items I have in the list and then add the article I get a

"The value you provided during this operation could not be validated" error.

In my file I've tried all of these combinations and none work:

item1;item2;item3

item1
item2
item3

item1;
item2;
item3;

1,item1
2,item2
3,item3

And then these with semicolons. This is what is written to the DD  
table in the database: a:1:{i:0;s:1:"1";} or else nothing is written  
to the db and I get the error above.

I was thinking "1" should be my items but I can't figure it out.

Is there anyone who can help me out?

Thanks,

Tim

-- 
Tim Stalker
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