Why can't I filter on a custom site column's contents?

We're using MOSS 2007 Beta 2, TR2. We've created a Site Column that's
the "lookup" type; call it "Department". I then created a custom list,
composed entirely of site columns and including the "Department" site
column. I then added some data to the table.

Next, I added a Content Query Web Part to another site, set to show
items from the custom list. If there are no filters, the entire
contents of the list are displayed. If, however, I add a filter that
set to look for specific values in the "Department" custom Site Column,
I get no results. Actually, I get the error message "There is a
problem with the query that this Web Part is issuing. Check the
configuration of this Web Part and try again."

Now, to make things extra interesting, I tried creating a column for
the list, making it a lookup column, allowing multiple values. This
worked perfectly - I was able to filter exactly the way I want. But
for standardization purposes, it isn't a workable solution.

So, why can't I set a Content Query Web Part to filter on a custom site
column's contents, when that column is on a custom list?

Oh my gosh!!! I've been scouring blogs for weeks trying to figure out why my
custom column was not appearing in the filters drop down. Your post was most
helpful. It seems pretty critical that the custom column type be "lookup"
(or at leat not "multiple lines of text"). That's the only way I could get
it to show up.

This is definitely not a workable solution. But, at least I know how it
works!

Thanks!

"Erik" wrote:
[..]

Single Line of Text also works. So, that makes this workable for us, but
definitely a point the MOSS Team should consider documenting!

"Donna" wrote:
[..]