After an extensive search of the MS knowledge base, I still can't find an
answer:

I have a simple SELECT query joining two tables, and I use the query as the
data source for a form. One of the tables contains memo fields that I want
to display on the form. I have the "Unique Values" property set to "Yes" to
avoid getting duplicate results. When I run the query, the memo fields are
truncated at 255 characters. This only happens when the "Unique Values"
property is set to "Yes". I know that Access will only use the first 255
characters of a Memo field to do comparisons for a Parameter query, and the
"Unique Values = Yes" setting does cause internal comparisons to take place
when Access runs my SELECT query, even though it's not a Paramater query.
However, I've found nothing that says memo fields will be truncated in the
result set in any scenario! Is there a way around this? Or is it an
"undocumented feature" of MS Jet . . .

(Using MS Jet version 4.0.6218.0)