Bex got limitation in rows and colums

Earlier i have upto 1 lakhs rows and columns in excel 2005 for BEX, later after installing excel 2007 it has got limitation upto 75,000. So how can i eliminate those limiatations in the BEx analyzer. Its not problem with excel upgradation as my microsoft support person said its not problem with excel. I thnk it could be with BEx. Could any one suggest me on this. Thanks in Advance..