Same error was discussed on the codeplex-page at http://ssisextensions.codeplex.com/discussions/434570, see the reply from mcpunjabi on Thu at 4:22 PM.

I downloaded that link, and it installed without issues, even Toolbox...

Honestly, I haven't spent too much time looking for a fix, but understanding the fact that DTS is depreciated in SQL2005, and with the plan to some time migrate them...