Functoids in Toolbox Empty?

Couple of day ago, I stumbled up with this problem: Functoids are not there in the toolbox while I was creating a BizTalk Map. When I right-clicked the toolbox and selected add items, I found the Functoid tab of the Customize Toolbox dialog box is empty.

I was trying to add those functoids by browsing the exact dll, but I could not find what is the DLLs name. But I got back all the functoids, after I clicked the Reset button in the Customize Toolbox dialog box. It must have reset all the changes in the other tabs as well.