Why In Reporting Services MDX query disappears after leaving "Data" tab.

Q: In Reporting Services MDX query disappears after leaving "Data" tab. How to fix this?

A: Problem clarification:
In Business Development Intelligence Studio (BIDS) you design a MDX query using Query Builder. But after you leave "Data" tab and come back, you see that all your selections disappear and you back to empty query builder.
We noticed this problem on Microsoft Windows Vista client computers that do not have all updates on Visual Studio 2005.

To fix this problem on Windows Vista PC you have to apply:

• Visual Studio 2005 Service Pack 1
• Visual Studio 2005 Service Pack 1 Update for Windows Vista

Also you should look into this KB article:

FIX: A query disappears in the MDX query designer, and you cannot modify a report in Layout view when you create the report in Business Intelligence Development Studio in SQL Server 2005