Matlab interprets SQL Server bigint as string

I have some queries against a SQL Server 2012 64bit instance, on the table the columns are defined as:

- float - bit - decimal - bigint - bigint

the float and bit are recogized by Matlab as numbers, however the decimal and the bigint columns are strings, which again causes a very inefficient conversion.

Anybody having a hint or idea where the problem could be ?

I'm using MATLAB Version 7.13.0.564 (R2011b)

[Friedrich]

Which driver do you use? What is your SQL query?

[Andreas]

I didn't write the database interface myself, but from what I can see sqloledb is used as a provider, and then an ADODB.connection is created and a ComObj.Execute(query) is performed. The query is a SELECT * FROM a table valued function. The function returns the correct data types when I check within SSMS.