Using GROUP BY and COUNT

I am having trouble running a query that uses a left join, group by, and
count on the table that is left joined.

I am using FreeTDS v0.91 with unixODBC, PHP 5.3.10, and SQL Server 2008. I
have my connection to use the 7.2 protocol. I am attempting to run the
following query:

SELECT COUNT(o0_.orderItemId) AS sclr0
FROM Membership m1_
LEFT JOIN OrderItem o0_ ON m1_.membershipId = o0_.membershipId
GROUP BY m1_.membershipId

This query only throws an error when there is a Membership that has no
records in the OrderItem table. If I run this query in SQL Server itself,
it runs with no issues and returns 0 for the Membership that has no
OrderItems.

When I try to run this query from FreeTDS, I receive this error:

SQLSTATE[24000]: Invalid cursor state: 0 [FreeTDS][SQL Server]Invalid
cursor state (SQLFetchScroll[0] at
/builddir/build/BUILD/php-5.3.10/ext/pdo_odbc/odbc_stmt.c:537)

Does anyone know why I would receive this error? I remember encountering a
similar error when I was attempting to loop through two result sets at
once, but this is a single query.

This error only happens when I use the COUNT() function on the joined table
and there is a case where there aren't any records in the joined table.
This query works from FreeTDS when all Memberships have at least one record
in OrderItem.

Does anyone know what could be causing this issue or how I could resolve it?

Thank you!