Query won't exe. on a Win98 pc.

[shkrebs]

Hi there.

I've been working with a Q in Access -97 on my pc which is a Windows 2000 Adv.Svr. and everything is working fine. Then today I was going to exe the same Q from a Win 98 (800Mhz, 128Mb) and I get the error '3071: Q is too complex..."
I've checked that all the same tools, drivers, helpprg., etc etc is installed and it seems OK.
Since my pc is the only Adv.Svr. here then it's a kind of important that I find a solution

The Q who initiates the error is this:

SELECT Left([Cabecera Facturacion].[C postal],2) AS PostalGruppe, Sum([Lineas Facturacion].[Uds Servidas]) AS NrDeLibros, Sum([Lineas Facturacion].[Importe Neto]) AS FactSin, [Cabecera Facturacion].[% Dto Com], Sum([Cabecera Facturacion].BaseImp1) AS FactCon
FROM [Cabecera Facturacion] INNER JOIN [Lineas Facturacion] ON ([Cabecera Facturacion].Numero = [Lineas Facturacion].Numero) AND ([Cabecera Facturacion].Serie = [Lineas Facturacion].Serie)
GROUP BY Left([Cabecera Facturacion].[C postal],2), [Cabecera Facturacion].[% Dto Com], [Lineas Facturacion].Producto
HAVING ((([Lineas Facturacion].Producto)="olhistpp1"));

Any ideas?¿?¿?¿?¿?¿?¿?¿?¿

Best regards