SAP BO Webi working very slow

Hi,

I am using SAP BO 4.0, working on webi reports.

I have a problem ,my webi runs very slow, it takes around 2-3 mins to open then also if i click on the window it hangs.For making any small change it takes 2-3 mins .Its really testing my patience.Its working like that from starting <working for last 3 months>

Please let me know what can be the issue for this behavior and also any resolution for the same.

Regards,

Javed