LINQ-to-SQL Query Returning No Results?

I have a query using LINQ-to-SQL. It queries an underlying database table Rooms. It uses Where conditions to narrow down the results, namely:

Gender.
Current Occupancy < Max Occupancy
Available Flag is Checked

I know this should return results but it keeps returning an empty set. Any ideas? Code is below

Dim selectedHalls = (From sh In dbHalls.Rooms _
Where sh.gender = Session("gender").ToString _
Where sh.max_occupancy > sh.current_occupancy _
Where sh.is_available = 1 _
Select sh.building_name).Distinct()

UPDATE: I've verified that the issue is with the statement where sh.is_available = 1, which doesn't make sense since this is a bit field.