I open up an old report and when I want to modify the report, I have noticed that all the Report Items is missing from the Toolbox. I am seeing that there are multiple Textbox item showned repeatedly on the Toolbox.
To fix this issue I go into this folder and remove the following .tbd file.
%USERPROFILE%\Local Settings\Application Data\Microsoft\VisualStudio\8.0
Once you have removing all the .tbd files.
Right click on the Toolbox panel and select Reset Toolbox. Click on Yes to confirm your choice.
This will take a while so be patient while the toolbox is resetting.