Can't edit SSIS DataFlow task (repost in Western encoding)

Configuration:
SQL Server 2005 Std x64, version 9.00.3233 running on Win2003.

When trying to edit a Data Flow task of a new or existing (added) SSIS
package, the following error is displayed:

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Cannot show the editor for this task.

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ADDITIONAL INFORMATION:

The task returned an unsupported control editor type.
(Microsoft.DataTransformationServices.Design)

For help, click:
http://go.microsoft.com/fwlink?ProdName=Microsoft%u00ae+Visual+Studio%...ae+2005

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Reinstalling integration services did not work. The service is running under
Local System account.

The same error is displayed on another server of the same configuration,
therefore I don't believe it is a corruption of
either Integration services or client components.

Did anybody experience/solved such problem?

Thank you.