Visual Studio Query Builder filter

Apologies if this is largely a Visual Studio 2005 question. I'm posting
it here because I assume my problem is caused by the interaction between
psqlODBC and Visual Studio. I'm using psqlODBC 8.01.02.00.

When using the graphical Query Builder tool, you can specify a filter
for your query. For example, if you specify the filter for table column
x as " = sometext' then you get:
WHERE x = 'sometext'
in your query.

All well and good if the column is of type text, but if the column is of
type Boolean I can't figure out how to get the damn thing to accept my
filter. For example:
" = 't'"
" = t"
" = true"
etc...
all don't work, saying that the data is of the wrong type.

Ok, so you're wondering why I don't just write my query the good old
fashioned way? The problem is if the Query Builder doesn't like your
query, it spits the dummy when it tries to generate the FillBy and GetBy
queries needed to use VS 2005 TableAdaptors.

The only workaround I've found so far is to create a dummy function that
always returns true and use that in the filter, eg.
" = alwaysTrue(12345)"

Any ideas on how to get it to accept my filter as boolean so I don't
have to use this workaround?

Regards,

Patrick