Hi,
Can you please refer the following SAP Note:
1958613 - Optimizing the BEx Analyzer Performance - Known Corrections and Best Practice Guidelines
And, can you please apply latest patch of SAP GUI for Windows 7.30 and
latest patch for BI 7.0 ADDON FOR SAP GUI 7.30 and check whether it helps you.
Also, please refer the following SAP Note:
147519 - Maintenance strategy / deadlines for SAP GUI
Thanks & Regards,
Sapna