Configuring BDE for using with MS SQL 6.5 server

I use delphi 4.0 C/S

Can anyone help me in configuring the BDE 5.01 for connecting with MSSQL 6.5
I have  used  the NATIVE driver to MSSQL for the link.

In my application I use a TQUERY object to get my data. If I use a query
like this
SELECT tble1.x, tble1.y  FROM tble1, tble2  WHERE ...

then after certain time the BDE responce with an error :
"Opperation not applicable"  detailed -> Unable to open table !
(a select from one table gives no problems)

In the trace file from MSSQL we see two select statements logged,
one for all elements in tble1 and one for all the elements of tble 2
In the SQL trace from the BDE i see the same.

the select from the two tables is splitted out in two selects

The settings for the BDE MSSQL native driver are :

VERSION :             4.0
TYPE:                     SERVER
DDL32:                  SQLMSS32.DLL
HOSTNAME:         <name of workstation>
SERVERNAME:   <name of serverstation>
SQLQRYMODE:    server

other are default