SQLExtendedFetch

I've posted this already but I thought a new subject might help.. I have a script which connects to a MS SQL database, executes a query then displays the result. There are two identical Apache web servers and one MS SQL database server. When the script is ran on web server #1, all the results are returned correctly. Ran on server #2, however, some entries are missing. Same script, different result.. After looking into the Driver Manager's log and I found that SQLExtendedFetch is being called on server 2 (incomplete result) and SQLFetch on server 1 (correct result). Can someone please tell me when PHP calls SQLExtendedFetch in stead of SQLFetch? How can I configure PHP to use SQLFetch instead? Thanks a lot!