Visual Studio (2008) crash when trying to add pipeline components to toolbox

I have been working on a pipeline components library. I encountered a strange issue when I tried to add a new pipeline component which I have added to the library. Every time I tried to "Choose Items..." in the pipeline components toolbox and choosed BizTalk Pipeline Components tab, my visual studio 2008 crashed. I don't remember whether I have encountered the same problem when I used visual studio 2005.

Thanks to Thiago Almeida, I found the solution: add the pipeline components into the Toolbox when the entire solution closed.